Backporting InCallUI so to allow calls on nonOEM devices

VideoProfile#videoStateToString, TelecomManager#getLine1Number, and
TelecomManager#isVoiceMailNumber don't exist in the L sdk, so Compat
classes were added which duplicated the needed logic.

Bug=25776171
Change-Id: Ib546b8fbd802aa6f8f5c712e59b99716db4c6a7b