AI 144928: Make the uphill discarding ops functionality controllable via a Gservices flag

BUG=1725022

Automated import of CL 144928

core/java/android/provider/Settings.java

@@ -2442,6 +2442,12 @@ public final class Settings {
          */
         public static final String GMAIL_BUFFER_SERVER_RESPONSE = "gmail_buffer_server_response";
 
+        /**
+         * Controls whether Gmail will discard uphill operations that repeatedly fail. Value must be
+         * an integer where non-zero means true. Defaults to 1.
+         */
+        public static final String GMAIL_DISCARD_ERROR_UPHILL_OP = "gmail_discard_error_uphill_op";
+
         /**
          * Hostname of the GTalk server.
          */