Revert "Revert "Change battery tip text""

This reverts commit 39beb253.

Reason for revert: <start to implement>

Fixes: 121042353
Test: adb shell settings put global battery_tip_constants test_low_battery_tip=true
      Then go to Settings -> battery to see the text

Change-Id: I83cc187d5bfda5312410e91ee636373f305ef449