Revert "Replace hidden AudioManager.FLAG_FROM_KEY usage"

This reverts commit 03e1a19e0ba734994f9565b0f7dc588e4d7ae804.

Reason for revert: We'd better not to copy the hidden APIs, but instead we need to make them public or @SystemApi.

Change-Id: I53db4247a2fa9d949747588a73fe75c8f2dbb716
2 files changed