test(pkgJson): make expectations work for npm 5 to 7

[raphinesse]

Motivation and Context

In some cases, npm 7 causes the package.json to look slightly different than with npm 6. This PR changes our tests so that they work with both flavors.

Description

This PR addresses the following differences:

Saved GitHub URL format in package.json:

• npm 6: git+https://github.com/apache/cordova-android.git#4.1.x
• npm 7: github:apache/cordova-android#4.1.x

Empty devDependencies format in package.json:

• npm 6: {}
• npm 7: undefined

Testing

• Automated tests are passing with npm@6
• Automated tests are passing with npm@^7.2 and https://github.com/apache/cordova-fetch/pull/91 Except for one test that fails due to a bug in npm 7: https://github.com/npm/cli/issues/2339