Update helper method naming and add nullity check

Author: dlackty

firebase-inappmessaging-display/src/main/java/com/google/firebase/inappmessaging/display/FirebaseInAppMessagingDisplay.java

@@ -534,7 +534,7 @@ private void notifyFiamDismiss() {
   }
 
   private void launchUriIntent(Activity activity, Uri uri) {
-    if (shouldOpenWeb(uri) && supportsCustomTabs(activity)) {
+    if (ishttpOrHttpsUri(uri) && supportsCustomTabs(activity)) {
       // If we can launch a chrome view, try that.
       CustomTabsIntent customTabsIntent = new CustomTabsIntent.Builder().build();
       Intent intent = customTabsIntent.intent;
@@ -564,7 +564,10 @@ private boolean supportsCustomTabs(Activity activity) {
     return resolveInfos != null && !resolveInfos.isEmpty();
   }
 
-  private boolean shouldOpenWeb(Uri uri) {
+  private boolean ishttpOrHttpsUri(Uri uri) {
+    if (uri == null) {
+      return false;
+    }
     String scheme = uri.getScheme();
     return scheme != null && (scheme.equalsIgnoreCase("http") || scheme.equalsIgnoreCase("https"));
   }