[WebAppProvider] Change static port to deflake WebAppMover test

This test is flaky because sometimes the port is bound to already.
Hopefully this port is less-randomly-chosen?

Bug: 1162285
Change-Id: I03fff905afe05a6235be452aeb3223007b32aa45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2611752
Auto-Submit: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Phillis Tang <phillis@chromium.org>
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841214}

chrome/browser/web_applications/web_app_mover_browsertest.cc

@@ -30,7 +30,7 @@ class WebAppMoverBrowsertest : public InProcessBrowserTest {
     https_server_.AddDefaultHandlers(GetChromeTestDataDir());
     // Since the port is a part of the start_url, this needs to stay consistent
     // between the tests below.
-    CHECK(https_server_.Start(44221));
+    CHECK(https_server_.Start(16247));
     scoped_feature_list_.InitWithFeaturesAndParameters(
         {{features::kMoveWebApp,
           {{features::kMoveWebAppUninstallStartUrlPrefix.name,