Bug: 24112165 Update docs for protection level of CHANGE_NETWORK_STATE

Previously, when CHANGE_NETWORK_STATE's protection level was raised to
signature from normal, the documentation was not changed. This CL
addresses the documentation to reflect the correct protection level.

Change-Id: I0a4d2fcef5f30c58b38250865543e72b5eb1ab06
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 99e55bf..860a315 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1694,7 +1694,7 @@
         android:protectionLevel="signature|privileged" />
 
     <!-- Allows applications to change network connectivity state.
-         <p>Protection level: normal
+         <p>Protection level: signature
     -->
     <permission android:name="android.permission.CHANGE_NETWORK_STATE"
         android:description="@string/permdesc_changeNetworkState"