Adds utility method to fetch browser name.

JitsiMeetJS.js

         if (firePermissionPromptIsShownEvent === true) {
             window.setTimeout(function () {
                 if (!promiseFulfilled) {
-                    var browser = RTCBrowserType.getBrowserType()
-                        .split('rtc_browser.')[1];
-
-                    if (RTCBrowserType.isAndroid()) {
-                        browser = 'android';
-                    }
-
                     JitsiMediaDevices.emitEvent(
                         JitsiMediaDevicesEvents.PERMISSION_PROMPT_IS_SHOWN,
-                        browser);
+                        RTCBrowserType.getBrowserName());
                 }
             }, USER_MEDIA_PERMISSION_PROMPT_TIMEOUT);
         }

modules/RTC/RTCBrowserType.js

         return currentBrowser;
     },
 
+    /**
+     * Gets current browser name, split from the type.
+     * @returns {string}
+     */
+    getBrowserName: function () {
+        var browser = currentBrowser.split('rtc_browser.')[1];
+        if (RTCBrowserType.isAndroid()) {
+            browser = 'android';
+        }
+        return browser;
+    },
+
     /**
      * Checks if current browser is Chrome.
      * @returns {boolean}