healthd: Only use battery values that seems legit

On some devices, there are other sysfs paths having a "capacity"
node than just the battery, which can return a weirdo value. We
make sure we only use legit battery levels (> 0%).

Change-Id: I3caf34e7fed4b89f953ec98c486b53b8786c8f74
libutils: refbase: jellybean mr1 compat

Change-Id: Ideee0c3814a17b47f70fd612d27067fe19ae698d
core: readd DurationTimer

Neded for find5 prop camera

Change-Id: I88d66f0ca02604f496ce204e37e70d2516c54d15
fix up adb to prefer /sbin/sh if it exists

Change-Id: Ifa68efec387e6c12dc4bb2d0e764b8ecf96c0ad5