Add init() to avoid crash when creating ref in constructor.

This reverts commit 50899fb2696d2bb98a4807a237e124f566293f57.

Bug: 195717690
Fix: 195717690
Test: atest VtsHalTvTunerTargetTest
Change-Id: Icae435f1166e6cf2e2f235979e3d1d37d182d517
diff --git a/tv/tuner/aidl/default/Frontend.cpp b/tv/tuner/aidl/default/Frontend.cpp
index 78d8279..438f897 100644
--- a/tv/tuner/aidl/default/Frontend.cpp
+++ b/tv/tuner/aidl/default/Frontend.cpp
@@ -28,7 +28,7 @@
 namespace tv {
 namespace tuner {
 
-Frontend::Frontend(FrontendType type, int32_t id, Tuner* tuner) {
+Frontend::Frontend(FrontendType type, int32_t id, std::shared_ptr<Tuner> tuner) {
     mType = type;
     mId = id;
     mTuner = tuner;