toolchain: Update revisions for Android

Also add spirv-headers, a new dependency for shaderc.
diff --git a/build-android/shaderc_revision_android b/build-android/shaderc_revision_android
index 8187523..0c161a0 100644
--- a/build-android/shaderc_revision_android
+++ b/build-android/shaderc_revision_android
@@ -1 +1 @@
-4213a472474053f456464b7d00d14adf814ecc44
+c63df792b2d535734cd0d1e6111de7ca29dcb555