Run virtmanager with its new UID

Bug: 183583115
Test: start virtmanager
ps -AZ | grep virtmanager
u: r:virtmanager:s0             virtmanager   2453     1 10930880  4544 0                   0 S virtmanager

Change-Id: Ib98029e61ee094842859609271e4d26b30cd2a7b
diff --git a/apex/Android.bp b/apex/Android.bp
index fa3806f..bb73630 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -35,6 +35,8 @@
         "vm",
     ],
     filesystems: ["microdroid"],
+    prebuilts: ["com.android.virt.init.rc"],
+    file_contexts: ":com.android.virt-file_contexts",
 }
 
 apex_key {
@@ -47,3 +49,9 @@
     name: "com.android.virt.certificate",
     certificate: "com.android.virt",
 }
+
+prebuilt_etc {
+    name: "com.android.virt.init.rc",
+    src: "virtmanager.rc",
+    filename: "init.rc",
+}