AudioFlinger: allow small requested capacity for FAST path

AudioFlinger used to reject requests for the low latency FAST
path when the capacity was != mPipeFramesP2.
But if the caller requests < mPipeFramesP2 than we can just bump it
up to mPipeFramesP2 because the API allows that.

For example, on Pixel, mPipeFramesP2 is 4096

Bug: 80308183
Test: adb shell input_monitor_callback -pl -b4000 -m1
Test: should see performance mode 12 for LOW_LATENCY
Change-Id: I987067910de3194fb52370d0ea1626cffad6248c

services/audioflinger/Threads.cpp

@@ -7454,8 +7454,10 @@ sp<AudioFlinger::RecordThread::RecordTrack> AudioFlinger::RecordThread::createRe
             // we formerly checked for a callback handler (non-0 tid),
             // but that is no longer required for TRANSFER_OBTAIN mode
             //
-            // frame count is not specified, or is exactly the pipe depth
-            ((frameCount == 0) || (frameCount == mPipeFramesP2)) &&
+            // Frame count is not specified (0), or is less than or equal the pipe depth.
+            // It is OK to provide a higher capacity than requested.
+            // We will force it to mPipeFramesP2 below.
+            (frameCount <= mPipeFramesP2) &&
             // PCM data
             audio_is_linear_pcm(format) &&
             // hardware format