This video includes guide on how to install Greenify app on non rooted device to improve battery life performance.
All the below steps mentioned at https://greenify.uservoice.com/knowledgebase/articles/749142-how-to-grant-permissions-required-by-some-features
Step 1 – install adb drivers from https://adb.clockworkmod.com/
Step 2 – Enable usb debugging option on android phone
step 3 – Connect your phone to computer and enable file transfer option
Step 4 – Now you can see your device is connected to computer
Step 5 – Install Greenify application
Step 6 – Open command prompt
Step 7 – type “adb devices” — it will list your phone with device id
Step 8 – Grant below command one by one. 3rd command might fail, ignore that error.
adb -d shell pm grant com.oasisfeng.greenify android.permission.WRITE_SECURE_SETTINGS
adb -d shell pm grant com.oasisfeng.greenify android.permission.DUMP
adb -d shell pm grant com.oasisfeng.greenify android.permission.READ_APP_OPS_STATS
adb -d shell am force-stop com.oasisfeng.greenify
Step 9 – You are done. Turn on aggressive doze mode and notification from greenify settings.