Update shader declarations to use 'uniform' instead of 'in'

Bug: 184822190
Bug: 184821777
Test: ran on device with blur enabled
Change-Id: I11d561e57e996529d5bcb7b763c6e9f70b68a034
diff --git a/libs/renderengine/skia/filters/BlurFilter.cpp b/libs/renderengine/skia/filters/BlurFilter.cpp
index ec710d9..6dd4161 100644
--- a/libs/renderengine/skia/filters/BlurFilter.cpp
+++ b/libs/renderengine/skia/filters/BlurFilter.cpp
@@ -34,7 +34,7 @@
 
 BlurFilter::BlurFilter() {
     SkString blurString(R"(
-        in shader input;
+        uniform shader input;
         uniform float2 in_blurOffset;
         uniform float2 in_maxSizeXY;
 
@@ -60,8 +60,8 @@
     mBlurEffect = std::move(blurEffect);
 
     SkString mixString(R"(
-        in shader blurredInput;
-        in shader originalInput;
+        uniform shader blurredInput;
+        uniform shader originalInput;
         uniform float mixFactor;
 
         half4 main(float2 xy) {