Plugins should not require removing use_frameworks! from Podfile #9694
Description
Right now the Google Sign In example app has removed use_frameworks! from its Podfile.
If this line is added back, the pod install step fails with the following error.
[!] The 'Pods-Runner' target has transitive dependencies that include static binaries: (/Users/jackson/git/gsi42/example/ios/Pods/Google/Frameworks/GGLCore.framework and /Users/jackson/git/gsi42/example/ios/Pods/Google/Frameworks/GGLSignIn.framework)
See firebase/FirebaseUI-iOS#34 for an example of other devs struggling with this issue.
A related issue is that the FlutterFire plugins are also written assuming use_frameworks! is not in the Podfile. For example, the Firebase Analytics example app fails when use_frameworks! is added back to its Podfile.
<module-includes>:1:1: warning: umbrella header for module 'Flutter' does not include header 'FlutterAsyncMessageListener.h' [-Wincomplete-umbrella]
#import "Headers/Flutter.h"
^
<module-includes>:1:1: warning: umbrella header for module 'Flutter' does not include header 'FlutterJSONMessageListener.h' [-Wincomplete-umbrella]
<module-includes>:1:1: warning: umbrella header for module 'Flutter' does not include header 'FlutterMessageListener.h' [-Wincomplete-umbrella]
3 warnings generated.
In file included from /Users/jackson/git/firebase_analytics/ios/Classes/FirebaseAnalyticsPlugin.m:7:
/Users/jackson/git/firebase_analytics/example/ios/Pods/Headers/Private/Firebase/Firebase.h:1:9: fatal error: 'FirebaseAnalytics/FirebaseAnalytics.h' file not found
#import <FirebaseAnalytics/FirebaseAnalytics.h>
^
3 warnings and 1 error generated.
We should try to make our plugin system compatible with use_frameworks!, or if that's not possible for Google Sign In, at least make the Firebase plugins able to build with use_frameworks!.