Revert "Change input injection security model to require INJECT_..."

Revert submission 17125748-require-inject-events-permission

Reason for revert: b/228203157, b/228194124
Reverted Changes:
Ib0d66eff3:Change input injection security model to require I...
Ief1a2f10c:Update WindowInputTests after changing injection p...
Ie2d8d0c3d:Change input injection security model to require I...

Change-Id: Iab079575c41821f5330002e23dc13884676a5249
diff --git a/libs/input/android/os/InputEventInjectionResult.aidl b/libs/input/android/os/InputEventInjectionResult.aidl
index 3bc7068..34f10ec 100644
--- a/libs/input/android/os/InputEventInjectionResult.aidl
+++ b/libs/input/android/os/InputEventInjectionResult.aidl
@@ -29,8 +29,9 @@
     /* Injection succeeded. */
     SUCCEEDED = 0,
 
-    /* Injection failed because the injected event did not target the appropriate window. */
-    TARGET_MISMATCH = 1,
+    /* Injection failed because the injector did not have permission to inject
+     * into the application with input focus. */
+    PERMISSION_DENIED = 1,
 
     /* Injection failed because there were no available input targets. */
     FAILED = 2,