transcoding: change max back-to-back running time to 2min

bug: 177631807
test: CTS MediaTranscodeManager tests; transcoding unit tests.
Change-Id: Ib4c333805856c7c0cc581bbe7784bcbe7df28ce9
diff --git a/media/libmediatranscoding/include/media/TranscodingSessionController.h b/media/libmediatranscoding/include/media/TranscodingSessionController.h
index 2691201..2657889 100644
--- a/media/libmediatranscoding/include/media/TranscodingSessionController.h
+++ b/media/libmediatranscoding/include/media/TranscodingSessionController.h
@@ -107,7 +107,7 @@
         // Maximum allowed back-to-back start count.
         int32_t pacerBurstCountQuota = 10;
         // Maximum allowed back-to-back running time.
-        int32_t pacerBurstTimeQuotaSeconds = 180;  // 3-min
+        int32_t pacerBurstTimeQuotaSeconds = 120;  // 2-min
     };
 
     struct Session {