Fix precision issue in hillshade causing terrain with steps on Mali

devices

GitOrigin-RevId: 3edd9369bb19df4ff7ff291eab562e20ce621a9b

Author: Nelarius

src/shaders/hillshade_prepare.fragment.glsl

@@ -1,6 +1,6 @@
 precision highp float;
 
-uniform sampler2D u_image;
+uniform highp sampler2D u_image;
 in vec2 v_pos;
 uniform vec2 u_dimension;
 uniform float u_zoom;

test/integration/render-tests/hillshade/MAPSNAT-3205/expected.png

@@ -0,0 +1,35 @@
+{
+  "version": 8,
+  "metadata": {
+    "test": {
+        "height": 256,
+        "width": 256
+    }
+  },
+  "center": [-106.271426, 39.237098],
+  "zoom": 16,
+  "sources": {
+    "mapbox-dem": {
+      "type": "raster-dem",
+      "tiles": [
+        "local://tiles/{z}-{x}-{y}.png"
+      ],
+      "maxzoom": 16,
+      "tileSize": 514
+    }
+  },
+  "layers": [
+    {
+      "id": "background",
+      "type": "background",
+      "paint": {
+        "background-color": "white"
+      }
+    },
+    {
+      "id": "hillshade",
+      "type": "hillshade",
+      "source": "mapbox-dem"
+    }
+  ]
+}