Allow permissions to be runtime-only.

This adds the new runtime protection level flag that if set means
the permission can only be granted to apps that target runtime
permissions (>= M).

ANSWER_PHONE_CALLS has also been made runtime-only.

Bug: 30932767
Test: cts-tradefed run commandAndExit cts-dev -m CtsPermission2TestCases
Change-Id: I42b30414c808730f2d5961ca31b6e3db740b8cf7
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index e7a447c..8e7f9d2 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -913,7 +913,7 @@
         android:permissionGroup="android.permission-group.PHONE"
         android:label="@string/permlab_answerPhoneCalls"
         android:description="@string/permdesc_answerPhoneCalls"
-        android:protectionLevel="dangerous" />
+        android:protectionLevel="dangerous|runtime" />
 
 
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