configstore: use utility functions defined in ConfigStoreUtils.h

This change modifies existing implementation to get config values via
configstore by using utility functions defined in ConfigStoreUtils.h.

Specifically, as an example, the utility function getInt64() is used
for vsyncEventPhaseoffsetNs defined in ISurfaceFlingerConfigs.

Design doc: go/design-confighal
Bug: 34724435
Test: build, run

Change-Id: I82a9371a84902c1e185d619d77e4c2e3272f84db
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index cbc209d..b39692c 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -87,6 +87,7 @@
 #include <cutils/compiler.h>
 
 #include <android/hardware/configstore/1.0/ISurfaceFlingerConfigs.h>
+#include <configstore/Utils.h>
 
 #define DISPLAY_COUNT       1
 
@@ -100,22 +101,9 @@
 
 namespace android {
 
+using namespace android::hardware::configstore;
 using namespace android::hardware::configstore::V1_0;
 
-static sp<ISurfaceFlingerConfigs> getConfigs() {
-    static sp<ISurfaceFlingerConfigs> configs
-            = ISurfaceFlingerConfigs::getService();
-    return configs;
-}
-
-static int64_t getVsyncEventPhaseOffsetNs() {
-    int64_t ret = 1000000; // default value
-    getConfigs()->vsyncEventPhaseOffsetNs([&](OptionalInt64 value) {
-          if (value.specified) ret = value.value;
-    });
-    return ret;
-}
-
 // This is the phase offset in nanoseconds of the software vsync event
 // relative to the vsync event reported by HWComposer.  The software vsync
 // event is when SurfaceFlinger and Choreographer-based applications run each
@@ -136,7 +124,9 @@
 // the latency will end up being an additional vsync period, and animations
 // will hiccup.  Therefore, this latency should be tuned somewhat
 // conservatively (or at least with awareness of the trade-off being made).
-static int64_t vsyncPhaseOffsetNs = getVsyncEventPhaseOffsetNs();
+static int64_t vsyncPhaseOffsetNs = getInt64<
+        ISurfaceFlingerConfigs,
+        &ISurfaceFlingerConfigs::vsyncEventPhaseOffsetNs>(1000000);
 
 // This is the phase offset at which SurfaceFlinger's composition runs.
 static const int64_t sfVsyncPhaseOffsetNs = SF_VSYNC_EVENT_PHASE_OFFSET_NS;