Use SandboxContext in AbstractDeviceProfileTest

- Added a initializeForTesting method to SandboxContext
- Also made SandboxContext non-abstract, so it can be used in tests to inject mock MainThreadInitializedObject into the SandboxContext, this should avoid mocked MainThreadInitializedObject bled into another test

Test: presubmit
Flag: None
Bug: 303328913
Change-Id: I37157d81b08b80f1e90eacca7dc2ce482cd08aa4

src/com/android/launcher3/util/MainThreadInitializedObject.java

@@ -93,7 +93,7 @@ public class MainThreadInitializedObject<T> {
      * Abstract Context which allows custom implementations for
      * {@link MainThreadInitializedObject} providers
      */
-    public static abstract class SandboxContext extends ContextWrapper {
+    public static class SandboxContext extends ContextWrapper {
 
         private static final String TAG = "SandboxContext";
 
@@ -165,5 +165,14 @@ public class MainThreadInitializedObject<T> {
         protected <T> T createObject(MainThreadInitializedObject<T> object) {
             return object.mProvider.get(this);
         }
+
+        /**
+         * Put a value into mObjectMap, can be used to put mocked MainThreadInitializedObject
+         * instances into SandboxContext.
+         */
+        @VisibleForTesting
+        public <T> void putObject(MainThreadInitializedObject<T> object, T value) {
+            mObjectMap.put(object, value);
+        }
     }
 }