qaudiooutput_pulse: Don't start playback if resources are not granted.

For 2199a80bd5730749bffc01be3e1c24b53d739d36
resourcepolicyplugin: Emit resources released signal for acquiring resources as well.

For 92d6564e35b8adeadd29c77d4f1c3ee49159a6da
qaudiooutput_pulse: Use custom volume if setVolume() was called.

Use custom volume if the argument value is within acceptable range.
Without this change if full volume (1.0) is requested, the volume is
never applied to the stream.
qaudiooutput_pulse: Return wanted for output's state.

Return m_wantedState here. We don't want to fool cautious users who
check the state before performing an operation into thinking an output
is already stopped and no further action is required only for it to come
alive again when resources become available.

For 2199a80bd5730749bffc01be3e1c24b53d739d36
qgstreamerplayercontrol: Remove unnecessary call to stopReleaseTimer().

For fa01b52cde2355f87bd192a20f5530bed81bbc2a