Add ACCESS_NETWORK_STATE permission to core module

When common was split from core, this permission was moved
to common. However both modules need it.

PiperOrigin-RevId: 295690886

library/core/src/main/AndroidManifest.xml

@@ -14,4 +14,7 @@
      limitations under the License.
 -->
 
-<manifest package="com.google.android.exoplayer2.core" />
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.google.android.exoplayer2.core">
+  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+</manifest>