Include 1xRTT when updating set of RATs via "Allow 2G" toggle.

Update BITMASK_2G to include 1xRTT when disabling/enabling 2G
via toggle in Enable2gPreferenceController. This is to align
with TelephonyManager's NETWORK_CLASS_BITMASK_2G.

Bug: b/163168917
Test: m & atest -c Enable2gPreferenceControllerTest
Change-Id: Ia0e099b63a9089be8cd8bfd4211db9eb3c506fc3
diff --git a/src/com/android/settings/network/telephony/Enable2gPreferenceController.java b/src/com/android/settings/network/telephony/Enable2gPreferenceController.java
index 1fa4300..c780234 100644
--- a/src/com/android/settings/network/telephony/Enable2gPreferenceController.java
+++ b/src/com/android/settings/network/telephony/Enable2gPreferenceController.java
@@ -31,7 +31,8 @@
     private static final long BITMASK_2G =  TelephonyManager.NETWORK_TYPE_BITMASK_GSM
                 | TelephonyManager.NETWORK_TYPE_BITMASK_GPRS
                 | TelephonyManager.NETWORK_TYPE_BITMASK_EDGE
-                | TelephonyManager.NETWORK_TYPE_BITMASK_CDMA;
+                | TelephonyManager.NETWORK_TYPE_BITMASK_CDMA
+                | TelephonyManager.NETWORK_TYPE_BITMASK_1xRTT;
 
     private CarrierConfigManager mCarrierConfigManager;
     private TelephonyManager mTelephonyManager;