Add shaderc components to the NDK manifest.

(cherry picked from commit 43eef65c28c32d2eaba2af946c169d8feb7a60ed)
diff --git a/default.xml b/default.xml
index 3c86ead..53e42a4 100644
--- a/default.xml
+++ b/default.xml
@@ -12,6 +12,9 @@
   <project path="chromite" name="platform/external/chromite" />
   <project path="chromite/config" name="toolchain/ndk_chromite_config" />
   <project path="development" name="platform/development" groups="pdk-cw-fs" />
+  <project path="external/shaderc/glslang" name="platform/external/shaderc/glslang" />
+  <project path="external/shaderc/shaderc" name="platform/external/shaderc/shaderc" />
+  <project path="external/shaderc/spirv-tools" name="platform/external/shaderc/spirv-tools" />
   <project path="ndk" name="platform/ndk" />
   <project path="prebuilts/clang/darwin-x86/host/3.6" name="platform/prebuilts/clang/darwin-x86/host/3.6" groups="pdk,darwin" />
   <project path="prebuilts/clang/linux-x86/host/3.6" name="platform/prebuilts/clang/linux-x86/host/3.6" groups="pdk,linux" />