[BACKPORT] Config of LTE signal strength default value remove SNR

use_only_rsrp_for_lte_signal_bar_bool default value set
"true"

Bug: 146317112
Test: 1. atest SignalStrengthTest.java
2. atest cts/tests/tests/telephony/current/src/android/telephony/cts/SignalStrengthTest.java
Change-Id: I75d5719a743ce815990a17c640bfb15e47d7802a
Merged-In: Ifd8ba60f112832aac975974e5f29290ac48c18b2

Change-Id: I68b15bf5224a97c7d49ecfce423a3615622ee625