Add telephony shell command to force D2D communications enabled.

This command is used for CTS testing to force override D2D on.

Test: Added CTS test leveraging the new command.
Test: Manual test to verify command operation.
Bug: 183239479
Change-Id: I093ee1503182a78baa7527097731974fc9499f62

telephony/java/com/android/internal/telephony/ITelephony.aidl

@@ -2351,6 +2351,12 @@ interface ITelephony {
      */
     void setActiveDeviceToDeviceTransport(String transport);
 
+    /**
+     * Forces Device to Device communication to be enabled, even if the device config has it
+     * disabled.
+     */
+    void setDeviceToDeviceForceEnabled(boolean isForceEnabled);
+
     /**
      * Gets the config of RCS VoLTE single registration enabled for the carrier/subscription.
      */