Fix Chromium and Android build

I broke this when I removed the relative path to the third_party astc
include file in this change:
https://swiftshader-review.googlesource.com/c/SwiftShader/+/43269

Bug: none
Change-Id: I45de8a6159c69c893df4449f6c6e10b09a9e6fe4
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/43448
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>
diff --git a/src/Device/BUILD.gn b/src/Device/BUILD.gn
index 92e3d0d..71e0f3d 100644
--- a/src/Device/BUILD.gn
+++ b/src/Device/BUILD.gn
@@ -50,6 +50,7 @@
     "Renderer.cpp",
     "SetupProcessor.cpp",
     "VertexProcessor.cpp",
+    # TODO: Write Build.gn for third_party/astc-encoder
     "../../third_party/astc-encoder/Source/astc_block_sizes2.cpp",
     "../../third_party/astc-encoder/Source/astc_color_unquantize.cpp",
     "../../third_party/astc-encoder/Source/astc_decompress_symbolic.cpp",
@@ -68,6 +69,7 @@
     "..",
     "../../include",
     "../../third_party/SPIRV-Headers/include",
+    "../../third_party/astc-encoder/Source"
   ]
 
   defines = [
diff --git a/third_party/astc-encoder/Android.bp b/third_party/astc-encoder/Android.bp
index 0c81fa2..dd1edfe 100644
--- a/third_party/astc-encoder/Android.bp
+++ b/third_party/astc-encoder/Android.bp
@@ -31,7 +31,11 @@
         "Source",
     ],
 
+    export_include_dirs: [
+        "Source",
+    ]
+
     static_libs: [
         "swiftshader_debug",
     ]
-}
\ No newline at end of file
+}