Release SQLite page cache as much as it can

Call sqlite3_release_memory() until it returns 0

Signed-off-by: klozz <xxx.reptar.rawrr.xxx@gmail.com>
Revert "PEEK: Sensors improvements"
Because some devices not have Gyroscope and only use Accelerometer

This reverts commit f7c4a2cdc8ff84fcb87f7a0e999cc7b2a9f56d4c.
Updated Icons to android L :)

Change-Id: I6ebd855e5dbc088a3e204f49960fb497e41aa2d4
Signed-off-by: klozz <xxx.reptar.rawrr.xxx@gmail.com>
reverted recent land

Signed-off-by: klozz <xxx.reptar.rawrr.xxx@gmail.com>