Remove legacy definitions from BluetoothMetricsProto

BluetoothMetricsProto is still used to build
BluetoothRemoteDeviceInformation objects
for logging in bluetooth extension atoms,
but all other definitions are legacy and can
be removed.

Bug: 401588157
Test: m com.android.bt
Flag: EXEMPT, dead code removal
Change-Id: Ifc65be582b5af7ee29a39e901c242386da22486e