CEC: Modify Standby Mode Handler

Add standby mode handler for generic device. Earlier, only TV devices
would use the standby mode handler to filter messages or feature abort
them when in standby. This does not change the standby mode handling of
TV devices.

Test: atest
android.hdmicec.cts.playback.HdmiCecRemoteControlPassThroughTest#cect_hf4_8_13_AbortIncorrectMode
Bug: 211843422

Change-Id: Ie00e16231e385db0f2d280f088882d5d0f9a8add
Merged-In: Ie00e16231e385db0f2d280f088882d5d0f9a8add