Add libartpalette-system to microdroid

libartpalette-system is a run-time dependency of dex2oat.

Bug: 187547405
Test: dex2oat
Change-Id: I6bb46ecccc7d83227c9f150a0c39e922311b4d87
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index b878b3e..b454ea2 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -64,6 +64,7 @@
 
         // "com.android.art" requires
         "heapprofd_client_api",
+        "libartpalette-system",
 
         "apexd",
         "debuggerd",