Fix proguard for external cast extension, disable for internal

PiperOrigin-RevId: 233594542

extensions/cast/build.gradle

@@ -25,7 +25,6 @@ android {
     defaultConfig {
     defaultConfig {
         minSdkVersion project.ext.minSdkVersion
         minSdkVersion project.ext.minSdkVersion
         targetSdkVersion project.ext.targetSdkVersion
         targetSdkVersion project.ext.targetSdkVersion
-        consumerProguardFiles 'proguard-rules.txt'
     }
     }
 }
 }
 
 

extensions/cast/proguard-rules.txt

-# Proguard rules specific to the Cast extension.
-
-# DefaultCastOptionsProvider is commonly referred to only by the app's manifest.
--keep class com.google.android.exoplayer2.ext.cast.DefaultCastOptionsProvider
-
-# ExoCastOptionsProvider is commonly referred to only by the app's manifest.
--keep class com.google.android.exoplayer2.ext.cast.ExoCastOptionsProvider
-
-# Don't warn about gms
--dontwarn com.google.android.gms.**