No longer use flattened APEX packages in ART Buildbot targets. am: d2fbc95b18 am: f840ecb6cb

Original change: https://android-review.googlesource.com/c/device/generic/art/+/1823302

Change-Id: I6aea10e03c71e383f950edfd8b12d96f9c5dce01
diff --git a/BoardConfigCommon.mk b/BoardConfigCommon.mk
index e741375..dda4b09 100644
--- a/BoardConfigCommon.mk
+++ b/BoardConfigCommon.mk
@@ -21,10 +21,6 @@
 
 TARGET_CPU_SMP := true
 
-# Flatten APEX packages to make them simpler to use in
-# ART testing/benchmarking environments.
-TARGET_FLATTEN_APEX := true
-
 # Enable ART Module top level apex/sdk/module_export modules. When they are
 # enabled the ART Module prebuilts (packages/modules/ArtPrebuilt and
 # prebuilts/module_sdk/art) cannot be present with prefer:true in the build