HDMI: Update local active source in RequestActiveSourceAction callback

In RequestActiveSourceAction's callback local active source should be
updated. Until now only an <Active Source> message was broadcasted which is not enough since the internal active source is stil invalid.

Bug: 315141766
Test: atest HdmiCecLocalDeviceTvTest
Change-Id: I588b9586435283d64cfc94ecb81b63f6eff1fa3a