changes without context (#1485)

autosynth cannot find the source of changes triggered by earlier changes in this
        repository, or by version upgrades to tools such as linters.

.github/workflows/ci.yaml

@@ -1,7 +1,7 @@
 on:
   push:
     branches:
-      - master
+      - $default-branch
   pull_request:
 name: ci
 jobs:

synth.metadata

@@ -1,3 +1,55 @@
 {
-  "updateTime": "2021-04-15T15:12:20.509557Z"
+  "sources": [
+    {
+      "git": {
+        "name": ".",
+        "remote": "https://github.com/googleapis/nodejs-firestore.git",
+        "sha": "c2e01646401f72520a4775a1f678634667225e6d"
+      }
+    },
+    {
+      "git": {
+        "name": "googleapis",
+        "remote": "https://github.com/googleapis/googleapis.git",
+        "sha": "e7d77d65f0e05ce584c1a824c7ecab53b411498b",
+        "internalRef": "370589666"
+      }
+    },
+    {
+      "git": {
+        "name": "synthtool",
+        "remote": "https://github.com/googleapis/synthtool.git",
+        "sha": "6244244abd0da5ef750e3bbb63fa22ec6803b4db"
+      }
+    }
+  ],
+  "destinations": [
+    {
+      "client": {
+        "source": "googleapis",
+        "apiName": "firestore-admin",
+        "apiVersion": "v1",
+        "language": "nodejs",
+        "generator": "bazel"
+      }
+    },
+    {
+      "client": {
+        "source": "googleapis",
+        "apiName": "firestore",
+        "apiVersion": "v1beta1",
+        "language": "nodejs",
+        "generator": "bazel"
+      }
+    },
+    {
+      "client": {
+        "source": "googleapis",
+        "apiName": "firestore",
+        "apiVersion": "v1",
+        "language": "nodejs",
+        "generator": "bazel"
+      }
+    }
+  ]
 }