Restrict testing target to unit tests and enable testing.

Author: aashishpatil-g

.github/workflows/spm.yml

@@ -43,4 +43,4 @@ jobs:
       run: xcodebuild -list
     - name: iOS Unit Tests
     # TODO(aashishpatil-g): Change from spmbuildonly to spm when unit tests are fixed.
-      run: scripts/third_party/travis/retry.sh scripts/build.sh FirebaseDataConnect ${{ matrix.target }} spmbuildonly
+      run: scripts/third_party/travis/retry.sh scripts/build.sh FirebaseDataConnect ${{ matrix.target }} spm

Package.swift

@@ -50,13 +50,9 @@ let package = Package(
       path: "Sources"
     ),
     .testTarget(
-      name: "FirebaseDataConnectTests",
+      name: "FirebaseDataConnectUnit",
       dependencies: ["FirebaseDataConnect"],
-      path: "Tests",
-      exclude: ["Gen/KitchenSink/Package.swift"],
-      resources: [
-        .copy("Resources/fdc-kitchensink"),
-      ]
+      path: "Tests/Unit"
     ),
   ]
 )