SF: Flag guard setFrameRate() API

- LayerHistory is now always created
- Do not use LayerHistory when content detection flag is turned off.

Bug: 148428554
Test: atest CtsGraphicsTestCases:SetFrameRateTest
Test: Play YouTube video. When content detection flag is off,
      display runs at 90, otherwise at 60.
Test: adb shell /data/.../libsurfaceflinger_unittest
Change-Id: Iab8b79e16a5257c770d9ddd204cfe26d22de83b6
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.cpp b/services/surfaceflinger/SurfaceFlingerProperties.cpp
index 269cf94..1a611f5 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.cpp
+++ b/services/surfaceflinger/SurfaceFlingerProperties.cpp
@@ -297,6 +297,14 @@
     return defaultValue;
 }
 
+bool use_frame_rate_api(bool defaultValue) {
+    auto temp = SurfaceFlingerProperties::use_frame_rate_api();
+    if (temp.has_value()) {
+        return *temp;
+    }
+    return defaultValue;
+}
+
 #define DISPLAY_PRIMARY_SIZE 3
 
 constexpr float kSrgbRedX = 0.4123f;