Increase Gradle version to 7.1.3

lib_theme/build.gradle

@@ -1,5 +1,9 @@
 apply from: rootProject.file("library.gradle")
 
+android {
+    namespace 'no.nordicsemi.android.theme'
+}
+
 dependencies {
     implementation project(":lib_log")
 

lib_theme/src/main/AndroidManifest.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest package="no.nordicsemi.android.theme">
+<manifest>
 
 </manifest>