Declare MediaButtonReceiver for support-mediarouter-v7 testing am: 34bde96f69
Declare MediaButtonReceiver for support-mediarouter-v7 testing
am: 34bde96f69

Change-Id: I08053e3bf94f364c1e302ec964c0c7e97f7b2b51

AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,aosp-mirror/platform_frameworks_support,aosp-mirror/platform_frameworks_support,aosp-mirror/platform_frameworks_support,androidx/androidx,aosp-mirror/platform_frameworks_support,androidx/androidx,androidx/androidx,aosp-mirror/platform_frameworks_support,AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx