[RCS UCE] Check if the device supports UCE before creating UCE feature manager

Bug: 178239287
Test: atest -c CtsTelephonyTestCases:android.telephony.ims.cts.RcsUceAdapterTest
Change-Id: I57c17e885ccf29abb7a367aa0e9029a83f10d1b9
diff --git a/res/values/config.xml b/res/values/config.xml
index 7dd26bb..0fd9b4b 100644
--- a/res/values/config.xml
+++ b/res/values/config.xml
@@ -307,6 +307,9 @@
     <!-- Whether or not to support RCS VoLTE single registration  -->
     <bool name="config_rcsVolteSingleRegistrationEnabled">true</bool>
 
+    <!-- Whether or not to support RCS User Capability Exchange -->
+    <bool name="config_rcs_user_capability_exchange_enabled">true</bool>
+
     <!-- Whether or not to support device to device communication using RTP and DTMF communication
          transports. -->
     <bool name="config_use_device_to_device_communication">false</bool>