GPS NMEA: enhance gga fix qualtiy for sensor contributed fix

This enhancement will be enabled if CUSTOM_NMEA_GGA_FIX_QUALITY_ENABLED
is set to 1 in gps.conf.

PPP fix w/o sensor: fix quality will now be 59
PPP fix w sensor: fix quality will now be 69
RTK fixed fix w/ sensor: fix quality will now be 64
RTK float fix w/ sensor: 65
DGNSS and/or SBAS correction fix and w/ sensor: 62
GPS fix without correction but and w/ sensor: 61

Change-Id: I7bc1bb5504e023de40f271d97d31c602f27bd94e
CRs-fixed: 2537211
diff --git a/etc/gps.conf b/etc/gps.conf
index 1c977f8..3d88fbe 100644
--- a/etc/gps.conf
+++ b/etc/gps.conf
@@ -107,6 +107,31 @@
 ################################
 # NMEA provider (1=Modem Processor, 0=Application Processor)
 NMEA_PROVIDER=0
+
+# Customized NMEA GGA fix quality that can be used to tell
+# whether SENSOR contributed to the fix.
+#
+# When this configuration item is not enabled (set to any value that is not 1),
+# GGA fix quality conforms to NMEA standard spec as below:
+# PPP/DGNSS/SBAS correction fix w/ or w/o sensor: 2
+# RTK fixed fix w/ or w/o sensor: 4
+# RTK float fix w/ or w/o sensor: 5
+# SPE fix w/ or w/o sensor: 1
+# Sensor dead reckoning fix: 6
+#
+# When this configuration is enabled (set to 1), GGA fix quality
+# will be output as below:
+# PPP fix w/o sensor: 59,                  w/ sensor: 69
+# DGNSS/SBAS correction fix w/o sensor: 2, w/ sensor: 62
+# RTK fixed fix w/o sensor: 4,             w/ sensor: 64
+# RTK float fix w/o sensor: 5,             w/ sensor: 65,
+# SPE fix w/o sensor: 1,               and w/ sensor: 61
+# Sensor dead reckoning fix: 6
+#
+# any value that is not 1 - disabled
+# 1 - enabled
+CUSTOM_NMEA_GGA_FIX_QUALITY_ENABLED = 0
+
 # Mark if it is a SGLTE target (1=SGLTE, 0=nonSGLTE)
 SGLTE_TARGET=0