Support repurposing idle timer to work with kernel timer.

Idle timer would instead enable/disable hw vsyncs in accordance with
inactivity.

Bug: 130684082
Test: systrace
Change-Id: I289600fc41b7ded863c9486cf6c2ab6155b06550
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.cpp b/services/surfaceflinger/SurfaceFlingerProperties.cpp
index 3522429..c43d095 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.cpp
+++ b/services/surfaceflinger/SurfaceFlingerProperties.cpp
@@ -246,6 +246,14 @@
     return defaultValue;
 }
 
+bool support_kernel_idle_timer(bool defaultValue) {
+    auto temp = SurfaceFlingerProperties::support_kernel_idle_timer();
+    if (temp.has_value()) {
+        return *temp;
+    }
+    return defaultValue;
+}
+
 #define DISPLAY_PRIMARY_SIZE 3
 
 constexpr float kSrgbRedX = 0.4123f;