ROMControl: Lockscreen Theme Color [2/2]

PS2: Fix color dialog canceling action.
PS2: Change wording (due to framework update)

Change-Id: I987b194b2d3e5e48a444fa5914ea666aaf4cb784
RC: Move Low Battery warning from GeneralUI to Battery

Change-Id: I160110fea0b78dc139a7bdcbeb152acc47b48d90