external: update external revisions

Update external revisions for glslang, spirv-tools, spirv-headers, and
shaderc.

Change-Id: Ie1f4afe2d36a6d8e3d1e166c23372f8f6523cf59
diff --git a/build-android/spirv-headers_revision_android b/build-android/spirv-headers_revision_android
index ebb6f9f..952227b 100644
--- a/build-android/spirv-headers_revision_android
+++ b/build-android/spirv-headers_revision_android
@@ -1 +1 @@
-db5cf6176137003ca4c25df96f7c0649998c3499
+63e1062a194750b354d48be8c16750d7a4d0dc4e