chore(java): detect sample-secrets in build.sh (#619)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/da4ff212-b599-4184-9bb9-741b5a34fe24/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

Source-Link: googleapis/synthtool@bb854b6

.kokoro/build.sh

@@ -79,6 +79,11 @@ samples)
 
     if [[ -f ${SAMPLES_DIR}/pom.xml ]]
     then
+        for FILE in ${KOKORO_GFILE_DIR}/secret_manager/*-samples-secrets; do
+          [[ -f "$FILE" ]] || continue
+          source "$FILE"
+        done
+
         pushd ${SAMPLES_DIR}
         mvn -B \
           -Penable-samples \

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-asset.git",
-        "sha": "c14ff12019be589c7c725dbc412d88f2883c81fa"
+        "sha": "9e75b3f4c9ec62e5c29e65dafeca1fdc21c4f7ce"
       }
     },
     {
@@ -51,7 +51,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "0b064d767537e0675fc053e53fca473c5c701fb8"
+        "sha": "bb854b6c048619e3be4e8b8ce8ed10aa74ea78ef"
       }
     }
   ],