Mock init of PowerHalController in test

We have injected a MockedPowerHalController in PowerAdvisorTest, but it
will always run init once, which will try to connect a real PowerHAL.
This was resulting in a few error logs like SELinux denials.

Bug: 280438886
Test: libsurfaceflinger_unittest
Change-Id: Icbd0289cbeba95582eed01e61dcb748e2e167c24
diff --git a/include/powermanager/PowerHalController.h b/include/powermanager/PowerHalController.h
index 71a36d0..82e4551 100644
--- a/include/powermanager/PowerHalController.h
+++ b/include/powermanager/PowerHalController.h
@@ -53,7 +53,7 @@
           : mHalConnector(std::move(connector)) {}
     virtual ~PowerHalController() = default;
 
-    void init();
+    virtual void init();
 
     virtual HalResult<void> setBoost(hardware::power::Boost boost, int32_t durationMs) override;
     virtual HalResult<void> setMode(hardware::power::Mode mode, bool enabled) override;