Dedupe kokoro builds (#10400)

* Attempt to dedupe Bazel test

* Intentionally break a test to make sure presubmits still run

* Moving some shared configs to higher directories

* Adding root common.cfg

* Adding action cfgs at root directory

* Adding empty presubmit/continuous

* Going back to leaf directories

* Adding empty presubmit/continuous

* Unify continuous and presubmit configs

* Consolidate all presubmit/continuous into a common config file

* Revert "Intentionally break a test to make sure presubmits still run"

This reverts commit 978eb19f80ea46f4a0e07789f86e791c5f9790ac.

* Fixing POC config files
diff --git a/kokoro/linux/php_all/common.cfg b/kokoro/linux/php_all/common.cfg
new file mode 100644
index 0000000..dfa8037
--- /dev/null
+++ b/kokoro/linux/php_all/common.cfg
@@ -0,0 +1,11 @@
+# Config file for running tests in Kokoro
+
+# Location of the build script in repository
+build_file: "protobuf/kokoro/linux/php_all/build.sh"
+timeout_mins: 120
+
+action {
+  define_artifacts {
+    regex: "**/sponge_log.xml"
+  }
+}