Make sure to return false for empty classpath

Previously, the binder call was returning true causing the test to
fail.

Test: adb shell data/nativetest/installd_dexopt_test/installd_dexopt_test
Bug: 118818285
Bug: 118777746
Change-Id: I1a4c3ee4a0e9ed614c15c95f88489b6bf4e66fa5
diff --git a/cmds/installd/dexopt.cpp b/cmds/installd/dexopt.cpp
index 174ab21..b6038f9 100644
--- a/cmds/installd/dexopt.cpp
+++ b/cmds/installd/dexopt.cpp
@@ -2693,6 +2693,13 @@
         return false;
     }
 
+    // Return false for empty class path since it may otherwise return true below if profiles is
+    // empty.
+    if (classpath.empty()) {
+        PLOG(ERROR) << "Class path is empty";
+        return false;
+    }
+
     // Open and create the snapshot profile.
     unique_fd snapshot_fd = open_spnashot_profile(AID_SYSTEM, package_name, profile_name);