fix UI sample and tests, with jank

Change-Id: I5fec7ac782307b9d16387d5d3809b610be34fca5

Author: morganchen12

FirebaseAuthUI/FUIAuthStrings.m

@@ -137,6 +137,9 @@
     }
   }
   NSBundle *frameworkBundle = [FUIAuthUtils bundleNamed:bundleName];
+  if (frameworkBundle == nil) {
+    frameworkBundle = [NSBundle mainBundle];
+  }
   return [frameworkBundle localizedStringForKey:key value:nil table:table];
 }
 

FirebaseAuthUI/FUIAuthUtils.m

@@ -26,6 +26,10 @@ + (NSBundle *)bundleNamed:(NSString *)bundleName {
   NSBundle *frameworkBundle = nil;
   if (bundleName) {
     NSString *path = [[NSBundle mainBundle] pathForResource:bundleName ofType:@"bundle"];
+    if (path == nil) {
+      // Check framework resources if bundle isn't present in main bundle.
+      path = [[NSBundle mainBundle] pathForResource:bundleName ofType:@"framework"];
+    }
     frameworkBundle = [NSBundle bundleWithPath:path];
   } else {
     frameworkBundle = [NSBundle bundleForClass:[self class]];