benchmark: use getExternalFilesDir() to save results

Instead of getFilesDir(), use getExternalFilesDir() so that results
can be accessed using adb on a production build as well

Log the paths to files where results are saved

Also update AndroidTest.xml to not uninstall apk after the test as
results need to be preserved

Bug: 147247596
Test: atest com.android.media.benchmark.tests
     on a device with factory image

Change-Id: I78e447ab0cba89cd56e72f56562a8e50036e94a0

media/tests/benchmark/MediaBenchmarkTest/AndroidTest.xml

@@ -15,6 +15,7 @@
 -->
 <configuration description="Runs Media Benchmark Tests">
     <target_preparer class="com.android.tradefed.targetprep.TestAppInstallSetup">
+        <option name="cleanup-apks" value="false" />
         <option name="test-file-name" value="MediaBenchmarkTest.apk" />
     </target_preparer>
 

media/tests/benchmark/MediaBenchmarkTest/src/androidTest/java/com/android/media/benchmark/tests/DecoderTest.java

@@ -57,7 +57,7 @@ public class DecoderTest {
     private static final String mInputFilePath = mContext.getString(R.string.input_file_path);
     private static final String mOutputFilePath = mContext.getString(R.string.output_file_path);
     private static final String mStatsFile =
-            mContext.getFilesDir() + "/Decoder." + System.currentTimeMillis() + ".csv";
+            mContext.getExternalFilesDir(null) + "/Decoder." + System.currentTimeMillis() + ".csv";
     private static final String TAG = "DecoderTest";
     private static final long PER_TEST_TIMEOUT_MS = 60000;
     private static final boolean DEBUG = false;
@@ -114,6 +114,7 @@ public class DecoderTest {
         Stats mStats = new Stats();
         boolean status = mStats.writeStatsHeader(mStatsFile);
         assertTrue("Unable to open stats file for writing!", status);
+        Log.d(TAG, "Saving Benchmark results in: " + mStatsFile);
     }
 
     @Test(timeout = PER_TEST_TIMEOUT_MS)

media/tests/benchmark/MediaBenchmarkTest/src/androidTest/java/com/android/media/benchmark/tests/EncoderTest.java

@@ -57,7 +57,7 @@ public class EncoderTest {
     private static final String mInputFilePath = mContext.getString(R.string.input_file_path);
     private static final String mOutputFilePath = mContext.getString(R.string.output_file_path);
     private static final String mStatsFile =
-            mContext.getFilesDir() + "/Encoder." + System.currentTimeMillis() + ".csv";
+            mContext.getExternalFilesDir(null) + "/Encoder." + System.currentTimeMillis() + ".csv";
     private static final String TAG = "EncoderTest";
     private static final long PER_TEST_TIMEOUT_MS = 120000;
     private static final boolean DEBUG = false;
@@ -94,6 +94,7 @@ public class EncoderTest {
         Stats mStats = new Stats();
         boolean status = mStats.writeStatsHeader(mStatsFile);
         assertTrue("Unable to open stats file for writing!", status);
+        Log.d(TAG, "Saving Benchmark results in: " + mStatsFile);
     }
 
     @Test(timeout = PER_TEST_TIMEOUT_MS)

media/tests/benchmark/MediaBenchmarkTest/src/androidTest/java/com/android/media/benchmark/tests/ExtractorTest.java

@@ -50,8 +50,8 @@ public class ExtractorTest {
     private static Context mContext =
             InstrumentationRegistry.getInstrumentation().getTargetContext();
     private static final String mInputFilePath = mContext.getString(R.string.input_file_path);
-    private static final String mStatsFile =
-            mContext.getFilesDir() + "/Extractor." + System.currentTimeMillis() + ".csv";
+    private static final String mStatsFile = mContext.getExternalFilesDir(null) + "/Extractor."
+            + System.currentTimeMillis() + ".csv";
     private static final String TAG = "ExtractorTest";
     private String mInputFileName;
     private int mTrackId;
@@ -84,6 +84,7 @@ public class ExtractorTest {
         Stats mStats = new Stats();
         boolean status = mStats.writeStatsHeader(mStatsFile);
         assertTrue("Unable to open stats file for writing!", status);
+        Log.d(TAG, "Saving Benchmark results in: " + mStatsFile);
     }
 
     @Test

media/tests/benchmark/MediaBenchmarkTest/src/androidTest/java/com/android/media/benchmark/tests/MuxerTest.java

@@ -58,7 +58,7 @@ public class MuxerTest {
             InstrumentationRegistry.getInstrumentation().getTargetContext();
     private static final String mInputFilePath = mContext.getString(R.string.input_file_path);
     private static final String mStatsFile =
-            mContext.getFilesDir() + "/Muxer." + System.currentTimeMillis() + ".csv";
+            mContext.getExternalFilesDir(null) + "/Muxer." + System.currentTimeMillis() + ".csv";
     private static final String TAG = "MuxerTest";
     private static final Map<String, Integer> mMapFormat = new Hashtable<String, Integer>() {
         {
@@ -106,6 +106,7 @@ public class MuxerTest {
         Stats mStats = new Stats();
         boolean status = mStats.writeStatsHeader(mStatsFile);
         assertTrue("Unable to open stats file for writing!", status);
+        Log.d(TAG, "Saving Benchmark results in: " + mStatsFile);
     }
 
     @Test