Make transcode test app debuggable

Without this change, we can't change the compat values on the app
during the test on user builds.

Test: atest
android.mediaprovidertranscode.cts.TranscodeTest#testAppCompatNoTranscodeHevc
Bug: 186607181

Change-Id: I404bbdd5e0b84547a97dd187ad02733713af2b3e