TEMPORARY: Reintroduce button-backlight (and respective inactivity timeout)

The power manager rewrite from Change I1d7a52e98f0449f76d70bf421f6a7f245957d1d7
completely removed support for control of the button backlights, which makes
all capacitive buttons out there stay dark. The commit message in that change
mentions it hasn't been implemented _yet_, so this fix should be temporary
until upstream does their own implementation

Change-Id: I6094c446e0b8c23f57d30652a3cbd35dee5e821a
Wipe and re-create database on downgrade.

Not a very common situation but should fix some errors that could
 arise from flashing an old ROM over a new one, without wiping data.

Change-Id: I27f2a00396761105987830921bb3f8cb339d2171
SystemUI: do not collapse panels if keyevent was canceled.

Change-Id: I9af82e9fa2305142521075938dfd05521adeb9f4
Allow adjusting progress on touch events.

Change-Id: Ide0a7ae057a62f3631a32eeaa63f3e04dec5bf54
fb: start music player if headset is connected

and adjust volume stream as well. We do not make this configurable
it is always a good and common feature

Change-Id: I912e680c2c8407ea62062482ea147ca0b156423b