Access IMMS#mSettings only inside the lock

This is a preparation CL before addresssing Bug 35361128.

IMMS.MyPackageMonitor#isChangingPackagesOfCurrentUser() needs to be
called after taking a lock for IMMS#mMethodMap because it internally
relies on InputMethodManagerService#mSettings.

Test: Made sure that the device can boot and the IME is available.
Bug: 35361128
Change-Id: I66752a275f20f6ba33bc211ffb8d6fd269250c0d

services/core/java/com/android/server/InputMethodManagerService.java

@@ -727,7 +727,8 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
             mPackagesToMonitorComponentChange.add(packageName);
         }
 
-        private boolean isChangingPackagesOfCurrentUser() {
+        @GuardedBy("mMethodMap")
+        private boolean isChangingPackagesOfCurrentUserLocked() {
             final int userId = getChangingUserId();
             final boolean retval = userId == mSettings.getCurrentUserId();
             if (DEBUG) {
@@ -740,10 +741,10 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
 
         @Override
         public boolean onHandleForceStop(Intent intent, String[] packages, int uid, boolean doit) {
-            if (!isChangingPackagesOfCurrentUser()) {
-                return false;
-            }
             synchronized (mMethodMap) {
+                if (!isChangingPackagesOfCurrentUserLocked()) {
+                    return false;
+                }
                 String curInputMethodId = mSettings.getSelectedInputMethod();
                 final int N = mMethodList.size();
                 if (curInputMethodId != null) {
@@ -777,10 +778,10 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
 
         @Override
         public void onSomePackagesChanged() {
-            if (!isChangingPackagesOfCurrentUser()) {
-                return;
-            }
             synchronized (mMethodMap) {
+                if (!isChangingPackagesOfCurrentUserLocked()) {
+                    return;
+                }
                 InputMethodInfo curIm = null;
                 String curInputMethodId = mSettings.getSelectedInputMethod();
                 final int N = mMethodList.size();