Fix environment variable injection (#15318)

The environment variables `IN_TEST` and `METAMASK_DEBUG` were not
being set to `false` correctly. Instead those variables were being
skipped, and were resolved to `undefined` at runtime. This is confusing
because the other environment variables do not work that way - they can
be set to false.

The build script has been updated to ensure those two environment
variables are always set to `true` or `false` - never `undefined`.

Additionally, the `METAMASK_VERSION` environment variable was being
omitted from the `app-init.js` bundle. For the sake of consistency,
that has also been restored.

development/build/scripts.js

@@ -219,7 +219,11 @@ function createScriptTasks({
   const { dev, test, testDev, prod } = core;
   return { dev, test, testDev, prod };
 
-  function createTasksForScriptBundles({ taskPrefix, devMode, testing }) {
+  function createTasksForScriptBundles({
+    taskPrefix,
+    devMode = false,
+    testing = false,
+  }) {
     const standardEntryPoints = ['background', 'ui', 'content-script'];
     const standardSubtask = createTask(
       `${taskPrefix}:standardEntryPoints`,
@@ -401,6 +405,7 @@ async function createManifestV3AppInitializationBundle({
   policyOnly,
   shouldLintFenceFiles,
   applyLavaMoat,
+  version,
 }) {
   const label = 'app-init';
   // TODO: remove this filter for firefox once MV3 is supported in it
@@ -423,6 +428,7 @@ async function createManifestV3AppInitializationBundle({
     testing,
     policyOnly,
     shouldLintFenceFiles,
+    version,
   })();
 
   postProcessServiceWorker(
@@ -632,6 +638,7 @@ function createFactoredBuild({
                 policyOnly,
                 shouldLintFenceFiles,
                 applyLavaMoat,
+                version,
               });
             }
             break;