[AspireE2E][Linux] The start time in the dashboard Resources page is incorrect

[EmilyFeng97]

REGRESSION INFO: Also repro in Aspire 13.0.2

INSTALL STEPS

1. Clean machine: Linux Ubuntu 22.04.2
2. Install SDK 10.0.101
3. Install Aspire.ProjectTemplate:
   dotnet new install Aspire.ProjectTemplates@13.1.0-preview.1.25609.8 --force

REPRO STEPS

1. Open a normal Command Prompt
2. Use the following command to create an Aspire Starter App project
   dotnet new aspire-starter -o AspireStarterApp
3. Go to AspireStarterApp.AppHost project:
   cd AspireStarterApp/AspireStarterApp.AppHost
4. Run the project:
   dotnet run
5. Open the Dashboard URL in browser
6. View the "Start time" column on the "Resources" page

NOTE:

1. This issue does not repro on windows machine.
2. This issue does not repro in the "Timestamp" column on the Structured and Traces page.
3. This issue also repro on Aspire Python Starter project.

ACTUAL
The Start Time is incorrect.

RESULT

[karolz-ms]

DCP regression.

Is related to a fix we made for process start time for identifying whether a process is the same; we had to stop evaluating the full start time because that wasn't consistent on Linux (it could shift by several seconds on system time updates). We are reading time since machine boot, but adding it to epoch start.

When fixing, let's change the tests so that it verifies we are returning a value that is reasonably certain to be correct

[karolz-ms]

Introduced by https://github.com/microsoft/usvc-apiserver/pull/823