[PlanarReflection] Zero Initialize for EnvLightData

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightUtilities.hlsl

 EnvLightData InitSkyEnvLightData(int envIndex)
 {
     EnvLightData output;
+    ZERO_INITIALIZE(EnvLightData, output);
-    SETTER_FLOAT3(output, capturePositionWS, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, influenceExtents, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, blendDistancePositive, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, blendDistanceNegative, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, blendNormalDistancePositive, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, blendNormalDistanceNegative, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, boxSideFadePositive, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, boxSideFadeNegative, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, sampleDirectionDiscardWS, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, proxyPositionWS, float3(0.0, 0.0, 0.0));
-    SETTER_FLOAT3(output, proxyExtents, float3(0.0, 0.0, 0.0));
 
     return output;
 }