Add presubmit config for kokoro

BUG b/123360006

Change-Id: Ib986b6409d7ac1d2ced6ea3b9995b026f960fa3e
Reviewed-on: https://swiftshader-review.googlesource.com/c/24289
Tested-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
diff --git a/kokoro/gcp_ubuntu/presubmit.cfg b/kokoro/gcp_ubuntu/presubmit.cfg
new file mode 100644
index 0000000..a20f256
--- /dev/null
+++ b/kokoro/gcp_ubuntu/presubmit.cfg
@@ -0,0 +1,4 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Location of the continuous bash script in Git.
+build_file: "SwiftShader/kokoro/gcp_ubuntu/continuous.sh"