Add build.prop for microdroid

Bug: 181728482
Test: boot microdroid, adb shell getprop
Change-Id: Ief3064661d8a2fd715a69880e4024abcc8357be2
diff --git a/microdroid/build.prop b/microdroid/build.prop
new file mode 100644
index 0000000..52d073f
--- /dev/null
+++ b/microdroid/build.prop
@@ -0,0 +1,4 @@
+# build.prop for microdroid
+ro.apex.updatable=true
+ro.debuggable=1
+ro.adb.secure=0