Fix no features emitting.

Fix no features emitting by emitting if they are present.
Ignore emitting features if the current state is not valid.
No features are emitted on registration because consumers are not
registered to the source.
The following tests ar fixed
 ExtensionWindowLayoutComponent#testDisplayFeatures
 ExtensionWindowLayoutComponentTest#testSidecarHasSameDisplayFeatures
 ExtensionWindowLayoutComponentTest#testGetWindowLayoutInfo_windowRecreated_windowLayoutUpdates
 ExtensionWindowLayoutComponentTest#testGetWindowLayoutInfo_configChanged_windowLayoutUpdates
 ExtensionWindowLayoutComponentTest#testGetWindowLayoutInfo_windowRecreated_windowLayoutUpdates

Bug: 232354881
Test: atest CtsWindowManagerJetpackTestCases:ExtensionWindowLayoutComponent
Change-Id: Ia1f7631576bad0bbefdca0fea3308973c5514056