Add userdata partition to microdroid

Many programs need /data (especially /data/local/tmp) to properly work.
This change adds a basic unencrypted ext4 userdata partition to
microdroid. Eventually microdroid will support userdata encryption so
only VM can access /data.

Bug: 185767624
Test: atest MicrodroidHostTestCases
Test: log in to microdroid and test writing to /data
Change-Id: I115a8083ad6741fea9dedd61eca7194b1b5e5712
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index 2522679..5cffdb4 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -18,6 +18,7 @@
     "vendor",
     "debug_ramdisk",
     "mnt",
+    "data",
 
     "apex",
     "linkerconfig",
@@ -105,6 +106,7 @@
     name: "microdroid_vendor",
     use_avb: true,
     deps: [
+        "microdroid_fstab",
         "microdroid_plat_sepolicy_vers.txt",
         "microdroid_precompiled_sepolicy",
         "microdroid_precompiled_sepolicy.plat_sepolicy_and_mapping.sha256",
@@ -385,6 +387,11 @@
 }
 
 prebuilt_etc {
+    name: "microdroid_cdisk_userdata.json",
+    src: "microdroid_cdisk_userdata.json",
+}
+
+prebuilt_etc {
     name: "microdroid_payload.json",
     src: "microdroid_payload.json",
 }