Set base_dir of microdroid to system am: a313e56e87

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/1589311

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Idb982181de7b4081c2bebb04187ccd092f70da23
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index f163d77..012df71 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -10,6 +10,7 @@
     deps: [
         "init_second_stage",
     ],
+    base_dir: "system",
     file_contexts: "microdroid_file_contexts",
 }