Explicit init .rc user.

Set the user explicitly.

Bug: 276813155
Test: boot
Change-Id: I2401794c5555e0043a2458eac6dd254bab7b3ca6
diff --git a/microdroid_manager/microdroid_manager.rc b/microdroid_manager/microdroid_manager.rc
index 97d14b5..e257547 100644
--- a/microdroid_manager/microdroid_manager.rc
+++ b/microdroid_manager/microdroid_manager.rc
@@ -11,4 +11,5 @@
     # CAP_SETCAP is required to allow microdroid_manager to drop capabilities
     #   before executing the payload
     capabilities AUDIT_CONTROL SYS_ADMIN SYS_BOOT SETPCAP
+    user root
     socket vm_payload_service stream 0666 system system