adb: enable/disable verity expected overlayfs errors.

Expect EBUSY for overlayfs teardown, and ENOENT for setup.

Test: adb-remount-test.sh
Bug: 131614849
Change-Id: I0fb351d6d5fe758021c9e9043f57863c7a194c12
diff --git a/adb/daemon/set_verity_enable_state_service.cpp b/adb/daemon/set_verity_enable_state_service.cpp
index 889229f..49dce66 100644
--- a/adb/daemon/set_verity_enable_state_service.cpp
+++ b/adb/daemon/set_verity_enable_state_service.cpp
@@ -111,8 +111,11 @@
             WriteFdFmt(fd, "%s overlayfs for %s\n", enable ? "disabling" : "using", mount_point);
         }
     } else if (errno) {
-        WriteFdFmt(fd, "Overlayfs %s for %s failed with error %s\n", enable ? "teardown" : "setup",
-                   mount_point, strerror(errno));
+        int expected_errno = enable ? EBUSY : ENOENT;
+        if (errno != expected_errno) {
+            WriteFdFmt(fd, "Overlayfs %s for %s failed with error %s\n",
+                       enable ? "teardown" : "setup", mount_point, strerror(errno));
+        }
     }
     WriteFdFmt(fd, "Verity %s on %s\n", enable ? "enabled" : "disabled", mount_point);
     return true;