Backporting references to android.telecom.Call.Details

In L, Call.Details.CAPABILITY_* constants were found in
android.telecom.PhoneCapabilities, it has been verified that the
constant values match as needed.

In L, Call.Details.getExtras had all the information that was moved to
Call.Details.getIntentExtras in M

Added android.telecom.Call.Details compat class

Change-Id: I16d25173382575f351762e0e5b71775f1046fdd0