more accurate product-name regex

Summary:
Some projects define multiple targets, including app extensions, which are built with a “.appex” extension.   This fix prevents the buildProject method from selecting any app extension (e.g. a Today.appex today-widget extension) as the product name.

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When building our workspace, ReactNative was failing to install the app to the simulator because it calculated an incorrect path to the app itself.   It was attempting to install "Today.app" when it should have been installing "Remitly.app".   I discovered that ReactNative parses the build output to identify the generated app name, and that this was broken when the build also generated an app extension.  The f
Closes https://github.com/facebook/react-native/pull/13001

Differential Revision: D4735360

fbshipit-source-id: afeeb2073ccd65c95916b153fcde574b5343af8c

local-cli/runIOS/runIOS.js

@@ -157,7 +157,7 @@ function buildProject(xcodeProject, udid, scheme, configuration = 'Debug', launc
     });
     buildProcess.on('close', function(code) {
       //FULL_PRODUCT_NAME is the actual file name of the app, which actually comes from the Product Name in the build config, which does not necessary match a scheme name,  example output line: export FULL_PRODUCT_NAME="Super App Dev.app"
-      let productNameMatch = /export FULL_PRODUCT_NAME="?(.+).app/.exec(buildOutput);
+      let productNameMatch = /export FULL_PRODUCT_NAME="?(.+).app"?$/.exec(buildOutput);
       if (productNameMatch && productNameMatch.length && productNameMatch.length > 1) {
         return resolve(productNameMatch[1]);//0 is the full match, 1 is the app name
       }