Fix the missing lock in onPackageDataCleared()

As a preparation for supporting concurrent multi-user with
MyPackageMonitor, with this CL fixes a missing lock in

  MyPackageMonitor#onPackageDataCleared,

which was introduced recently [1].

As fields like

  InputMethodManager#mSettings
  InputMethodManager#mAdditionalSubtypeMap

need to be touched only within ImfLock, we still need an explicit lock
there.

 [1]: I159d9b7a2d1dcc8df478bb45d0be706d615724a2
      18a26c88a8c73d18b3aedf513ad4dc4c698fbf0e

Bug: 267124364
Bug: 309837937
Bug: 322062773
Test: manually tested the case.
Change-Id: Ida9e9143324ccf0e5bcff224fbb0e4e6650996b0
diff --git a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
index 3bd1e1a..c023993 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -1331,17 +1331,19 @@
 
         @Override
         public void onPackageDataCleared(String packageName, int uid) {
-            boolean changed = false;
-            for (InputMethodInfo imi : mSettings.getMethodList()) {
-                if (imi.getPackageName().equals(packageName)) {
-                    mAdditionalSubtypeMap.remove(imi.getId());
-                    changed = true;
+            synchronized (ImfLock.class) {
+                boolean changed = false;
+                for (InputMethodInfo imi : mSettings.getMethodList()) {
+                    if (imi.getPackageName().equals(packageName)) {
+                        mAdditionalSubtypeMap.remove(imi.getId());
+                        changed = true;
+                    }
                 }
-            }
-            if (changed) {
-                AdditionalSubtypeUtils.save(
-                        mAdditionalSubtypeMap, mSettings.getMethodMap(), mSettings.getUserId());
-                mChangedPackages.add(packageName);
+                if (changed) {
+                    AdditionalSubtypeUtils.save(
+                            mAdditionalSubtypeMap, mSettings.getMethodMap(), mSettings.getUserId());
+                    mChangedPackages.add(packageName);
+                }
             }
         }