Declare `ConversionResult` in `android` namespace am: 19418e32ed am: 37ba0178cc

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2482955

Change-Id: I2cf519d0f3de658e77b4d32a3abaa561fcca86f0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>