Reduce use of clearCommunicationDevice.

We can reduce the use of clearCommunicationDevice so that it is only
called at the end of a call.  When switching routes mid-call, there is no
need to call it.

To fix this, we pass the destination audio route's active/inactive status
into `setOrigRoute` and update the `PendingAudioRoute` with that.
When `AudioRoute#clearCommunicationDevice` is called, we'll now only
clear if we are transitioning to an inactive state.

Flag: com.android.server.telecom.flags.only_clear_communication_device_on_inactive
Fixes: 376781369
Test: Run Telecom unit tests.
Test: Swap between earpiece/speaker, disconnect call.
Test: Swap between earpiece/speaker/SCO, disconnect call.
Test: Swap between earpiece/speaker/LE, disconnect call.
Change-Id: Ibc444784d96d9bf99700ba52cf321fcdcbfc2ea0