Android 5.0 说明
Starting in Android 5.0, the system enforces a new uniqueness restriction on custom permissions
for apps that are signed with different keys. Now only one app on a device can define a given
custom permission (as determined by its name), unless the other app defining the permission is
signed with the same key. If the user tries to install an app with a duplicate custom permission
and is not signed with the same key as the resident app that defines the permission, the system blocks
the installation.
解释
所以当我们在Android 5.0以及以上系统中使用自定义权限的时候，如果两个APK具有相同的签名，那么就不能使用相同命名的自定义权限。