Duplicate symbols between GoogleOpenSource framework and GTMOAuth2 lib

[SotoiGhost]

Using Xamarin to implement Google Play Games Services for iOS I found that Play Games is not compatible with Sign-In v4.0.1 anymore because GoogleOpenSource framework (dependency of PlayGames) have duplicated symbols with GTMOAuth2 headers (dependency of Sign-In). Here's a list of duplicated symbols between libs:

'_kGTMOAuth2WebViewKey'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2ErrorMessageKey'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2WebViewStopKindKey'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2NetworkLost'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2ErrorInvalidRequest'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2ErrorInvalidClient'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2ErrorUnauthorizedClient'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2ErrorInvalidGrant'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_OBJC_CLASS_$_GTMOAuth2AuthorizationArgs'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_OBJC_METACLASS_$_GTMOAuth2AuthorizationArgs'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o) 
'_kGTMOAuth2FetchTypeUserInfo'.
error: Duplicate symbol in: GoogleOpenSource(GTMOAuth2Authentication.o) 
error: Duplicate symbol in: GTMOAuth2(GTMOAuth2Authentication.o)

Also, Play Games dependencies needs to be updated to replace GoogleOpenSource dependency with the new GTMOAuth2 and GoogleToolboxForMac/Logger open source projects.