wip set up JDK 17

Author: gnprice

.github/workflows/ci.yml

@@ -8,6 +8,11 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: 17
+
     - name: Clone Flutter SDK
       # We can't do a depth-1 clone, because we need the most recent tag
       # so that Flutter knows its version and sees the constraint in our