allow invalid inactive slot allow non-A/B devices added pt_BR translations (thanks to @igormiguell for the contribution)

Kernel Flasher is an Android app to flash, backup, and restore kernels. Features: Flash partition images and AK3 kernel zips Backup and Restore kernel partitions Mount, Map, and Resize vendor_dlkm Save dmesg, logcat, and ramoops Check for kernel updates Notes: When making a backup of the active slot, to save time, it is assumed that the kernel on disk is the same as the running kernel. The Check Kernel Version button can retrieve it from disk prior to backup. Depending on the method used, the updated contents of vendor_dlkm may not be immediately available for backup after flash or restore. This can be resolved by unmounting, unmapping, then remapping it. AK3 helper modules are not backed up.