Deprecate setMinimumSessionInterval

Author: allenktv

Firebase/Core/Public/FIRAnalyticsConfiguration.h

@@ -35,7 +35,8 @@ NS_SWIFT_NAME(AnalyticsConfiguration)
  * is 10 seconds.
  */
 - (void)setMinimumSessionInterval:(NSTimeInterval)minimumSessionInterval
-    DEPRECATED_MSG_ATTRIBUTE("Sessions are started immediately");
+    DEPRECATED_MSG_ATTRIBUTE(
+        "Sessions are started immediately. More information at https://bit.ly/2FU46av");
 
 /**
  * Sets the interval of inactivity in seconds that terminates the current session. The default