Drawable Renderer (#1570), Update shader sources

shaders/drawable.background.vertex.glsl

@@ -1,6 +1,8 @@
 layout (location = 0) in vec2 a_pos;
 layout (std140) uniform DrawableUBO {
     mat4 u_matrix;
+    vec2 u_world;
+    vec2 pad;
 };
 
 void main() {

shaders/drawable.fill.vertex.glsl

@@ -2,6 +2,8 @@ layout (location = 0) in vec2 a_pos;
 
 layout (std140) uniform DrawableUBO {
     mat4 u_matrix;
+    vec2 u_world;
+    vec2 pad;
 };
 
 #pragma mapbox: define highp vec4 color

shaders/drawable.fill_outline.vertex.glsl

@@ -1,7 +1,10 @@
 layout (location = 0) in vec2 a_pos;
 
-uniform mat4 u_matrix;
-uniform vec2 u_world;
+layout (std140) uniform DrawableUBO {
+    mat4 u_matrix;
+    vec2 u_world;
+    vec2 pad;
+};
 
 out vec2 v_pos;