MediaSession: Enforce max name length on broadcast receivers too

The previous change in ag/35590474 only checked the length of component names set via MediaSession.setMediaButtonReceiver(PendingIntent) [1] and
not via
MediaSession.setMediaButtonBroadcastReceiver(android.content.ComponentName) [2] as highlighted in b/433250316#comment72.

[1] https://developer.android.com/reference/android/media/session/MediaSession#setMediaButtonBroadcastReceiver(android.content.ComponentName)

[2] https://developer.android.com/reference/android/media/session/MediaSession#setMediaButtonBroadcastReceiver(android.content.ComponentName)

Bug: 433250316
Test: Presubmit
Flag: EXEMPT BUGFIX
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:d09400d72573c2e6124ae28dd9bb68139c9598a5
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:23c44648eaddf4cb17ff6b77975a5f43c1293048
Merged-In: I7ef6bb0015f2501559793129ca62881911e7b9eb
Change-Id: I7ef6bb0015f2501559793129ca62881911e7b9eb