Add debug log on Power HAL support and connection status

Allow enabling power hint through system property

Bug: 195990840
Test: manual test
Change-Id: I3694eda0ab1f1474a367d02b8d61ae602c5ba993
diff --git a/services/surfaceflinger/FlagManager.cpp b/services/surfaceflinger/FlagManager.cpp
index bd3cf74..f8ad8f6 100644
--- a/services/surfaceflinger/FlagManager.cpp
+++ b/services/surfaceflinger/FlagManager.cpp
@@ -96,7 +96,8 @@
 }
 
 bool FlagManager::use_adpf_cpu_hint() const {
-    std::optional<bool> sysPropVal = std::nullopt;
+    std::optional<bool> sysPropVal =
+            doParse<bool>(base::GetProperty("debug.sf.enable_adpf_cpu_hint", "").c_str());
     return getValue("AdpfFeature__adpf_cpu_hint", sysPropVal, false);
 }