Add internal plumbing to DPM for encryption

* Add code to persist per-admin setting
* Add hooks for OS-level tie-in (is supported, get / set status)
* Add 3rd API call to get OS status (irrespective of admin settings)
* Remove "REQUESTED" status, no longer relevant with 3rd API
* Fixed bug that impacted global proxy settings
* Update api/11.xml to match current.xml

Bug: 3346770
Change-Id: I56bdf9a7894f6ca4842402c7b82ddb3caf4b37b9
diff --git a/core/java/android/app/admin/IDevicePolicyManager.aidl b/core/java/android/app/admin/IDevicePolicyManager.aidl
index d3b5cf3..e8caca1 100644
--- a/core/java/android/app/admin/IDevicePolicyManager.aidl
+++ b/core/java/android/app/admin/IDevicePolicyManager.aidl
@@ -76,7 +76,8 @@
     ComponentName getGlobalProxyAdmin();
 
     int setStorageEncryption(in ComponentName who, boolean encrypt);
-    int getStorageEncryption(in ComponentName who);
+    boolean getStorageEncryption(in ComponentName who);
+    int getStorageEncryptionStatus();
 
     void setActiveAdmin(in ComponentName policyReceiver, boolean refreshing);
     boolean isAdminActive(in ComponentName policyReceiver);