Marking @SystemApi permissions @hide too.

Bug: 28287631
Change-Id: Ie0375620689263ebafd6850f2261e090f09521b1
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 22cf279..0665a53 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1020,7 +1020,8 @@
         android:protectionLevel="signature|privileged" />
 
     <!-- @SystemApi Allows an application to send SMS to premium shortcodes without user permission.
-         <p>Not for use by third-party applications. -->
+         <p>Not for use by third-party applications.
+         @hide -->
     <permission android:name="android.permission.SEND_SMS_NO_CONFIRMATION"
         android:protectionLevel="signature|privileged" />
 
@@ -1031,7 +1032,8 @@
 
     <!-- @SystemApi Allows an application to receive emergency cell broadcast messages,
          to record or display them to the user.
-         <p>Not for use by third-party applications. -->
+         <p>Not for use by third-party applications.
+         @hide -->
     <permission android:name="android.permission.RECEIVE_EMERGENCY_BROADCAST"
         android:protectionLevel="signature|privileged" />