Testing component in Android App SDLC?

"Automated testing is an integral part of the development lifecycle."

In android app proejcts we've implemented MVP, Rx with Retrofit and Content Provider/SQLite, dagger. Evey android apps will always have server communication, storing data in local database, complex ui like naviagtion drawer and recycler view etc, and difficult navigation flow of application.

What we want to achieve?

• Few test cases which should be tested every time before we deliver the apk to client or release on play store?(20-30% automate testing)
• List of test cases of business logic in, which can not be auto tested because whatever reason like complex ui, naviagtion flow etc (40-60% manual testing)
• Continuous Integration

Based on above, there are few questions,

• What to test in auto and manual, how to decide that?
• In automate testing, where to test in MVP layer?
• what kind of general business logic should auto test for mobile apps - like registration, login, forgot password, update profile etc?
• What type of testing should perform for android apps - unit testing, functional testing, integration testing, manual testing, performance testing, regression testing
• Which tool to use - android testing support library, espresso, uiautomator, Robotium, roboelectric, appium, selendroid, mockito, JUnit

(Feel free to improve check list as we don't know best practices for testing module in SDLC for android mobile app.) originally asked, here.