fix: revert gradle namespaces, add release Firebase config

Reverted gradle namespace changes (io.pezkuwichain.wallet -> io.novafoundation.nova)
because they break R class references in Kotlin code.

Internal namespaces are NOT user-visible, so this is acceptable for minimum rebrand.
User-visible elements are all properly branded as Pezkuwi.

Added google-services.json for release variant.

feature-governance-api/build.gradle

@@ -7,7 +7,7 @@ android {
 
     }
 
-    namespace 'io.pezkuwichain.wallet.feature_governance_api'
+    namespace 'io.novafoundation.nova.feature_governance_api'
 }
 
 dependencies {