improve android example: remove second launcher and fix the manifest

[radetsky]

During the example test, I found the following deficiencies:

1. Two application icons instead of one.
2. SecureMessage test was not happening.
3. The app was not loading on the API 35 + 16k page memory platform.

Fixed:

1. fixed manifest. Now there is one icon. And the application loads adequately.
2. Added code to start SecureMessage activity.

The example application was tested on:

1. Android 10 phone
2. API 33 Simulator
3. API 34 Simulator
4. API 35 Simulator
5. API 35+16k Simulator

Also, I think we should accept the PR #1051
It works on 35+ Simulators and does not crash the test application.

Checklist

• The [coding guidelines] are followed

[vixentael]

does it work for older androids or only for new?

[radetsky]

I answered you in private, but yes, I tested it on Android 10 phone + API 33-35 on Simulators.
Thank you.