AudioManager Blocks The Main Thread

We discovered that setting
`audioManager.mode = AudioManager.MODE_IN_COMMUNICATION`

blocks the main thread. However, assigning the mode value in a child thread resolved the issue and didn't affect functionality. I'd like to know why this happens.

Start by reproducing the assignment to audioManager.mode with AudioManager.MODE_IN_COMMUNICATION on the main thread and in a child thread. Trace the AudioManager call path to determine why the main thread blocks, then document the cause and expected behavior or identify the affected code path for a fix.

Written by the indexing model from the issue text.