adb-remount-test: Adb shell command could return 0 or 255 if device is
disconnected

Background: aosp/I25f740bd222263fcb3c501def38977db6af1e0d9

Bug: 327552188
Test: abtd
Change-Id: Ida33bfa00887e8ac358e057fc37fd45095ccc26b
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index 7ac7a16..526c761 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -1081,7 +1081,9 @@
 LOG RUN "Testing adb disable-verity -R"
 
 T=$(adb_date)
-adb_su disable-verity -R >&2 ||
+adb_su disable-verity -R >&2
+err=${?}
+[[ ${err} -eq 0 || ${err} -eq 255 ]] ||
   die -t "${T}" "disable-verity -R failed"
 sleep 2
 adb_wait "${ADB_WAIT}" ||
@@ -1192,7 +1194,9 @@
 LOG RUN "Testing adb remount -R"
 
 T=$(adb_date)
-adb_su remount -R </dev/null >&2 ||
+adb_su remount -R </dev/null >&2
+err=${?}
+[[ ${err} -eq 0 || ${err} -eq 255 ]] ||
   die -t "${T}" "adb remount -R failed"
 sleep 2
 adb_wait "${ADB_WAIT}" ||