SuspendSepolicyTests: Use target device grep

Some vendors reported issue running the test since thier host
environment was missing the path to grep command.

Use the target device grep instead.

Bug: 381369000
Test: atest SuspendSepolicyTests
Change-Id: Id891e9bcdfe00992b98124319e821d0bbb663282
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>

suspend/1.0/default/SuspendSepolicyTests.sh

diff --git a/suspend/1.0/default/SuspendSepolicyTests.sh b/suspend/1.0/default/SuspendSepolicyTests.sh
index 0dd2a3e..8bab96d 100755
--- a/suspend/1.0/default/SuspendSepolicyTests.sh
+++ b/suspend/1.0/default/SuspendSepolicyTests.sh
@@ -32,7 +32,9 @@
 }
 
 has_wakeup_attr() { #path
-    adb shell ls -dZ "$1" | grep -q "$wakeup_attr"
+    local _path="$1"
+
+    adb shell "ls -dZ $_path | grep -q $wakeup_attr"
     return $?
 }