health: Drop HealthServiceWrapperHidl.init.

Having a separate init function is a bad contract because
the client may not call it. Replace it with the constructor.

This reduces technical debt.

Test: pass
Change-Id: I3828903b006c32eb6898d36e64326520ef601ba8

services/core/java/com/android/server/health/HealthServiceWrapper.java

@@ -102,8 +102,7 @@ public abstract class HealthServiceWrapper {
             @NonNull HealthServiceWrapperHidl.IServiceManagerSupplier hidlServiceManagerSupplier,
             @NonNull HealthServiceWrapperHidl.IHealthSupplier hidlHealthSupplier)
             throws RemoteException, NoSuchElementException {
-        HealthServiceWrapperHidl service = new HealthServiceWrapperHidl();
-        service.init(hidlRegCallback, hidlServiceManagerSupplier, hidlHealthSupplier);
-        return service;
+        return new HealthServiceWrapperHidl(
+                hidlRegCallback, hidlServiceManagerSupplier, hidlHealthSupplier);
     }
 }

services/core/java/com/android/server/health/HealthServiceWrapperHidl.java

@@ -56,12 +56,6 @@ final class HealthServiceWrapperHidl extends HealthServiceWrapper {
     // Last IHealth service received.
     private final AtomicReference<IHealth> mLastService = new AtomicReference<>();
 
-    /**
-     * init should be called after constructor. For testing purposes, init is not called by
-     * constructor.
-     */
-    HealthServiceWrapperHidl() {}
-
     private static void traceBegin(String name) {
         Trace.traceBegin(Trace.TRACE_TAG_SYSTEM_SERVER, name);
     }
@@ -181,7 +175,7 @@ final class HealthServiceWrapperHidl extends HealthServiceWrapper {
      * @throws NullPointerException when supplier is null
      */
     @VisibleForTesting
-    void init(
+    HealthServiceWrapperHidl(
             @Nullable Callback callback,
             @NonNull IServiceManagerSupplier managerSupplier,
             @NonNull IHealthSupplier healthSupplier)