`InstrumentationActivityInvoker$BootstrapActivity` starts a separate process...

### Description

`ActivityScenario` launches `InstrumentationActivityInvoker$BootstrapActivity` before it launches the requested activity.
In application modules this launches a separate process for the your Test APK, which slows down tests.

In library modules this launches in the same process (there is only one APK).

This can lead to behaviour differences of the same test depending on if it is in a library or app module.

### Steps to Reproduce

### Expected Results

BootstrapActivity launches in the process under test, not a new separate process.

### Actual Results

BootstrapActivity launches in a new separate process for application modules with a separate test APK.

### AndroidX Test and Android OS Versions
1.3.0
API 30

Start by tracing how ActivityScenario launches InstrumentationActivityInvoker$BootstrapActivity and how the process is selected for application modules with a separate test APK. Compare that behavior with library modules, then verify that BootstrapActivity launches in the process under test without changing the requested activity flow.

Written by the indexing model from the issue text.