Adjust the LTE signal bar mapping.

The new mapping are

  Four  bars: RSRP >= -95dBm
  Three bars: -105 dBm <= RSRP < -95 dBm
  Two   bars: -115 dBm <= RSRP < -105 dBm
  One   bars: RSRP < -115 dBm
  No    bars: No Service

bug:5640958
Change-Id: I9efabaeac33b624ea0a58a4d3760169dff6544f6