Camera: Handle the case of calling Uid being cameraserver

With HAL1-camera2 legacy implementation, the getCameraCharacteristics
may be called without camera permission. So the cameraserver's Uid is
used in that case.

AppOpsManager returns MODE_IGNORED when the cameraserver's Uid is passed.
Do not treat this as an error case.

Bug: 153511543
Test: On Pixel 2 device, run "adb root; adb shell setprop
persist.camera.HAL3.enabled 0; adb reboot", then "atest
cts/tests/camera/CaptureRequestTest"

Change-Id: I29aaa2045b14233537c737bf0738fbc32422540e

services/camera/libcameraservice/CameraService.cpp

@@ -2742,7 +2742,7 @@ CameraService::BasicClient::BasicClient(const sp<CameraService>& cameraService,
         mClientPackageName(clientPackageName),
         mClientPid(clientPid), mClientUid(clientUid),
         mServicePid(servicePid),
-        mDisconnected(false),
+        mDisconnected(false), mUidIsTrusted(false),
         mAudioRestriction(hardware::camera2::ICameraDeviceUser::AUDIO_RESTRICTION_NONE),
         mRemoteBinder(remoteCallback)
 {
@@ -2791,6 +2791,8 @@ CameraService::BasicClient::BasicClient(const sp<CameraService>& cameraService,
     if (getCurrentServingCall() != BinderCallType::HWBINDER) {
         mAppOpsManager = std::make_unique<AppOpsManager>();
     }
+
+    mUidIsTrusted = isTrustedCallingUid(mClientUid);
 }
 
 CameraService::BasicClient::~BasicClient() {
@@ -2905,7 +2907,9 @@ status_t CameraService::BasicClient::startCameraOps() {
             return PERMISSION_DENIED;
         }
 
-        if (res == AppOpsManager::MODE_IGNORED) {
+        // If the calling Uid is trusted (a native service), the AppOpsManager could
+        // return MODE_IGNORED. Do not treat such case as error.
+        if (!mUidIsTrusted && res == AppOpsManager::MODE_IGNORED) {
             ALOGI("Camera %s: Access for \"%s\" has been restricted",
                     mCameraIdStr.string(), String8(mClientPackageName).string());
             // Return the same error as for device policy manager rejection

services/camera/libcameraservice/CameraService.h

@@ -323,6 +323,7 @@ public:
         const uid_t                     mClientUid;
         const pid_t                     mServicePid;
         bool                            mDisconnected;
+        bool                            mUidIsTrusted;
 
         mutable Mutex                   mAudioRestrictionLock;
         int32_t                         mAudioRestriction;

services/camera/libcameraservice/api2/CameraOfflineSessionClient.cpp

@@ -197,7 +197,9 @@ status_t CameraOfflineSessionClient::startCameraOps() {
             return PERMISSION_DENIED;
         }
 
-        if (res == AppOpsManager::MODE_IGNORED) {
+        // If the calling Uid is trusted (a native service), the AppOpsManager could
+        // return MODE_IGNORED. Do not treat such case as error.
+        if (!mUidIsTrusted && res == AppOpsManager::MODE_IGNORED) {
             ALOGI("Offline Camera %s: Access for \"%s\" has been restricted",
                     mCameraIdStr.string(), String8(mClientPackageName).string());
             // Return the same error as for device policy manager rejection