Remove duplicated declaration of required OSGi execution environment (g…

…oogle#2711)

The bnd-maven-plugin used to generate the OSGi metadata can determine
the required EE automatically based on the version of the generated
class-files. This avoids inconsistencies if the release target is raised
in the future.

gson/bnd.bnd

@@ -3,8 +3,6 @@ Bundle-Name: ${project.name}
 Bundle-Description: ${project.description}
 Bundle-Vendor: Google Gson Project
 Bundle-ContactAddress: ${project.parent.url}
-Bundle-RequiredExecutionEnvironment: JavaSE-1.7, JavaSE-1.8
-Require-Capability: osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=1.7))"
 
 # Optional dependency for JDK's sun.misc.Unsafe
 # https://bnd.bndtools.org/chapters/920-faq.html#remove-unwanted-imports-