Simplify tutorials

[reyang]

Changes

• Changed the metrics tutorials so we only have one "getting-started" rather than 4.
• Changed ConsoleExporter so by default we don't do periodic export.

[codecov]

Codecov Report

Merging #2406 (be40be0) into main (78baf7c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2406   +/-   ##
=======================================
  Coverage   80.28%   80.28%           
=======================================
  Files         232      232           
  Lines        7500     7500           
=======================================
  Hits         6021     6021           
  Misses       1479     1479           

Impacted Files	Coverage Δ
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	97.14% <0.00%> (-2.86%)	⬇️
...Telemetry/Internal/SelfDiagnosticsEventListener.cs	97.63% <0.00%> (+0.78%)	⬆️