Pass correct install user when creating sessions

This CL passes the correct install user when creating sessions in
StagingManager and effectively reverts ag/6901350.

Add a test to ensure b/129397974 is not regressed as described in
b/158222747#comment11.

Fix: 129744602
Fix: 158222747
Test: atest MultiUserRollbackTest#testStagedRollback
Change-Id: I718992240aa76898ff9e4220ea6a769ee8cd61f5
diff --git a/tests/RollbackTest/Android.bp b/tests/RollbackTest/Android.bp
index a23df92..4f5a305 100644
--- a/tests/RollbackTest/Android.bp
+++ b/tests/RollbackTest/Android.bp
@@ -53,6 +53,9 @@
     name: "MultiUserRollbackTest",
     srcs: ["MultiUserRollbackTest/src/**/*.java"],
     libs: ["tradefed"],
+    static_libs: [
+        "frameworks-base-hostutils",
+    ],
     test_suites: ["general-tests"],
     test_config: "MultiUserRollbackTest.xml",
 }