Allow user to block individual apps from resuming.

This adds a new section to the media controls settings screen with a
list of apps that could potentially be used for resumption. If an app is
toggled off it will be added to a list of apps which will not persist in
QS, even when resumption is on.

Also updated the strings on this setting page to match UX
recommendation, so the default toggle state is now on.

Bug: 161813143
Bug: 159852516
Test: manual
Test: atest SettingsProviderTests
Test: make -j40 RunSettingsRoboTests ROBOTEST_FILTER="ResumableMedia"
Change-Id: Id3de52419ffba233469396dd47439428201e5e00
Merged-In: Id3de52419ffba233469396dd47439428201e5e00