Remove unused InputMethodInfo#isEncryptionAware().

This logically reverts a previous CL [1], which added
InputMethodInfo#isEncryptionAware() for File-Based Encryption (FBE)
support, since it turns out that the method in question is unnecessary
to make InputMethodManagerService encryption-aware.

  [1]: Icf921fe3661eccf4a589b08b616d05decc561356
       69811a98f161a04af8e8ec9978c3a5efe1ea0f29

Bug: 26279466
Change-Id: Ia4884bf5922ad453d4b9e5e3c6f0d17b36dc205d
diff --git a/core/java/android/view/inputmethod/InputMethodInfo.java b/core/java/android/view/inputmethod/InputMethodInfo.java
index d97f8af..281babe 100644
--- a/core/java/android/view/inputmethod/InputMethodInfo.java
+++ b/core/java/android/view/inputmethod/InputMethodInfo.java
@@ -428,18 +428,6 @@
         }
     }
 
-    /**
-     * @return {@code true} if the {@link android.inputmethodservice.InputMethodService} is marked
-     * to be Encryption-Aware.
-     * @hide
-     */
-    public boolean isEncryptionAware() {
-        if (mService == null || mService.serviceInfo == null) {
-            return false;
-        }
-        return mService.serviceInfo.encryptionAware;
-    }
-
     public void dump(Printer pw, String prefix) {
         pw.println(prefix + "mId=" + mId
                 + " mSettingsActivityName=" + mSettingsActivityName