test: lower debounceTime in browser builder tests

The current `debounceTime` values are unnecessarily high, resulting in slow test execution. Reducing these times will improve efficiency.

(cherry picked from commit 4d88743)

Author: alan-agius4

packages/angular_devkit/build_angular/src/builders/browser/specs/lazy-module_spec.ts

@@ -98,7 +98,7 @@ describe('Browser Builder lazy modules', () => {
       const run = await architect.scheduleTarget(target, overrides);
       await run.output
         .pipe(
-          debounceTime(1500),
+          debounceTime(1000),
           tap((buildEvent) => {
             buildNumber++;
             switch (buildNumber) {

packages/angular_devkit/build_angular/src/builders/browser/specs/rebuild_spec.ts

@@ -22,7 +22,7 @@ describe('Browser Builder rebuilds', () => {
   const target = { project: 'app', target: 'build' };
   // Rebuild tests are especially sensitive to time between writes due to file watcher
   // behaviour. Give them a while.
-  const rebuildDebounceTime = 3000;
+  const rebuildDebounceTime = 1000;
   let architect: Architect;
 
   beforeEach(async () => {

packages/angular_devkit/build_angular/src/builders/browser/specs/service-worker_spec.ts

@@ -147,7 +147,7 @@ describe('Browser Builder service worker', () => {
 
     await run.output
       .pipe(
-        debounceTime(3000),
+        debounceTime(1000),
         tap((buildEvent) => {
           expect(buildEvent.success).toBeTrue();