Docs: fix broken image link in platforms architecture doc

Change-Id: Ie6a9f6c475633336b45cb74719c2cf0724e54971
diff --git a/docs/html/guide/platform/Images/android-stack_2x.png b/docs/html/guide/platform/images/android-stack_2x.png
similarity index 100%
rename from docs/html/guide/platform/Images/android-stack_2x.png
rename to docs/html/guide/platform/images/android-stack_2x.png
Binary files differ