Update documentation for the READ_PHONE_STATE permission

Bug: 26413825
Change-Id: I58d21ddd6e2ad1cc724648db5839d711d96663fb
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 60f05448..8abb7e2 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -706,7 +706,9 @@
         android:description="@string/permgroupdesc_phone"
         android:priority="500" />
 
-    <!-- Allows read only access to phone state.
+    <!-- Allows read only access to phone state, including the phone number of the device,
+         current cellular network information, the status of any ongoing calls, and a list of any
+         {@link android.telecom.PhoneAccount}s registered on the device.
          <p class="note"><strong>Note:</strong> If <em>both</em> your <a
          href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min">{@code
          minSdkVersion}</a> and <a