MainClear: remove obsolete check for multi-volume FDE

It is never the case that '!isExternalStorageEmulated() &&
!isExternalStorageRemovable() && isExtStorageEncrypted()', so stop
checking for this.

It's easy to see that even just the last part, isExtStorageEncrypted(),
is never true, since it checks whether the property "vold.decrypt" is
non-empty.  That system property was only set on devices that used FDE
(Full Disk Encryption), and FDE support was removed in Android T.

Moreover, the full condition of '!emulated && !removable && FDE'
actually checked for devices that used multi-volume FDE, which
apparently was never actually used, and was removed 8 years ago by vold
commit 87999173dd79 (http://ag/423222).  This is consistent with the
fact that this code was added 11 years ago by commit 2a32192329
(http://ag/134210), when probably this feature was still planned.

Bug: 208476087
Change-Id: I4c2b5c9aed8812367a70d0dd1bbcc94008fec529

src/com/android/settings/MainClear.java

@@ -44,7 +44,6 @@ import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
-import android.sysprop.VoldProperties;
 import android.telephony.euicc.EuiccManager;
 import android.text.TextUtils;
 import android.util.Log;
@@ -309,12 +308,9 @@ public class MainClear extends InstrumentedFragment implements OnGlobalLayoutLis
          * If the external storage is emulated, it will be erased with a factory
          * reset at any rate. There is no need to have a separate option until
          * we have a factory reset that only erases some directories and not
-         * others. Likewise, if it's non-removable storage, it could potentially have been
+         * others.
-         * encrypted, and will also need to be wiped.
          */
-        boolean isExtStorageEmulated = Environment.isExternalStorageEmulated();
+        if (Environment.isExternalStorageEmulated()) {
-        if (isExtStorageEmulated
-                || (!Environment.isExternalStorageRemovable() && isExtStorageEncrypted())) {
             mExternalStorageContainer.setVisibility(View.GONE);
 
             final View externalOption = mContentView.findViewById(R.id.erase_external_option_text);
@@ -323,9 +319,7 @@ public class MainClear extends InstrumentedFragment implements OnGlobalLayoutLis
             final View externalAlsoErased = mContentView.findViewById(R.id.also_erases_external);
             externalAlsoErased.setVisibility(View.VISIBLE);
 
-            // If it's not emulated, it is on a separate partition but it means we're doing
+            mExternalStorage.setChecked(false);
-            // a force wipe due to encryption.
-            mExternalStorage.setChecked(!isExtStorageEmulated);
         } else {
             mExternalStorageContainer.setOnClickListener(new View.OnClickListener() {
 
@@ -457,11 +451,6 @@ public class MainClear extends InstrumentedFragment implements OnGlobalLayoutLis
         }
     }
 
-    private boolean isExtStorageEncrypted() {
-        String state = VoldProperties.decrypt().orElse("");
-        return !"".equals(state);
-    }
-
     private void loadAccountList(final UserManager um) {
         View accountsLabel = mContentView.findViewById(R.id.accounts_label);
         LinearLayout contents = (LinearLayout) mContentView.findViewById(R.id.accounts);