fix(BuildHelper): get package name from ApplicationInfo

[yuzhiqiang1993]

Platforms affected

Android

Motivation and Context

for example
if the Activity is not at the to level of the package,like this.

The package name of my project is com/yzq/cordovademo. But I get the Unable to get the BuildConfig, is this built with ANT? exception when I use the camera plugin.

Description

We don't have to worry about the Activity hierarchy by getting the package name like ctx.getApplicationInfo().packageName

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-commenter]

Codecov Report

Merging #1575 (c0da2f6) into master (d4bfd50) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1575   +/-   ##
=======================================
  Coverage   72.13%   72.13%           
=======================================
  Files          21       21           
  Lines        1751     1751           
=======================================
  Hits         1263     1263           
  Misses        488      488           

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[breautek]

Thank you @yuzhiqiang1993 for helping us maintain cordova-android. This patch will land in our cordova-android@12 release.