disable device test on blueline-28 for transport-runtime (#4630)

Author: yifanyang

transport/transport-runtime/transport-runtime.gradle

@@ -54,7 +54,9 @@ firebaseLibrary {
     testLab {
         enabled = true
 
-        device 'model=blueline,version=28' // Pixel3
+        // TODO(yifany): Blueline-28 was added in #4558, but has never passed.
+        //               Disabling for now. Re-enable later if needed.
+        // device 'model=blueline,version=28' // Pixel3
         device 'model=walleye,version=27' // Pixel2
         device 'model=Nexus4,version=22'
         device 'model=Nexus7,version=21'