ci: re-enable chrome mobile tests on android (angular#32447)

With 63dff9c, we temporarily disabled
the chrome mobile tests on Android because the launched browsers weren't
able to load the karma page through the tunnel.

The Saucelabs support responded to a ticket that we opened and said that
there were issues with those browsers which are now resolved.

PR Close angular#32447

browser-providers.conf.js

@@ -29,11 +29,8 @@ var CIconfiguration = {
   'Edge': {unitTest: {target: 'SL', required: false}, e2e: {target: null, required: true}},
   'Android4.4': {unitTest: {target: 'SL', required: false}, e2e: {target: null, required: true}},
   'Android5': {unitTest: {target: 'SL', required: false}, e2e: {target: null, required: true}},
-  // TODO: Re-enable Android6 and Android7 as these are just temporarily disabled because
-  // the browsers don't capture. This seems to be because the browsers are not able to
-  // establish a connection to the karma server through the tunnel.
-  'Android6': {unitTest: {target: 'SL', required: false}, e2e: {target: null, required: true}},
-  'Android7': {unitTest: {target: 'SL', required: false}, e2e: {target: null, required: true}},
+  'Android6': {unitTest: {target: 'SL', required: true}, e2e: {target: null, required: true}},
+  'Android7': {unitTest: {target: 'SL', required: true}, e2e: {target: null, required: true}},
   'Safari7': {unitTest: {target: 'BS', required: false}, e2e: {target: null, required: true}},
   'Safari8': {unitTest: {target: 'BS', required: false}, e2e: {target: null, required: true}},
   'Safari9': {unitTest: {target: 'BS', required: false}, e2e: {target: null, required: true}},