chore: add express to default list of instrumented plugins

[mayurkale22]

Which problem is this PR solving?

• add express to default list of instrumented plugins

/cc @vmarchaud

[codecov-io]

Codecov Report

Merging #914 into master will decrease coverage by 1.42%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #914      +/-   ##
==========================================
- Coverage   94.32%   92.90%   -1.43%     
==========================================
  Files         245      244       -1     
  Lines       10970    10959      -11     
  Branches     1061     1064       +3     
==========================================
- Hits        10348    10181     -167     
- Misses        622      778     +156     

Impacted Files	Coverage Δ
...entelemetry-core/test/context/B3Propagator.test.ts	45.53% <0.00%> (-54.47%)	⬇️
packages/opentelemetry-core/test/utils/url.test.ts	50.00% <0.00%> (-50.00%)	⬇️
...pentelemetry-core/test/internal/validators.test.ts	50.00% <0.00%> (-50.00%)	⬇️
...elemetry-core/test/trace/spancontext-utils.test.ts	55.55% <0.00%> (-44.45%)	⬇️
...lemetry-core/test/trace/ProbabilitySampler.test.ts	61.70% <0.00%> (-38.30%)	⬇️
...s/opentelemetry-core/test/trace/tracestate.test.ts	65.06% <0.00%> (-34.94%)	⬇️
...ckages/opentelemetry-core/test/platform/id.test.ts	66.66% <0.00%> (-33.34%)	⬇️
...ntelemetry-core/test/trace/NoRecordingSpan.test.ts	71.42% <0.00%> (-28.58%)	⬇️
...ackages/opentelemetry-core/src/platform/node/id.ts	75.00% <0.00%> (-25.00%)	⬇️
...entelemetry-core/test/common/ConsoleLogger.test.ts	76.47% <0.00%> (-23.53%)	⬇️
... and 43 more

[vmarchaud]

I'm fine with that if we release #910 with it :)

[mayurkale22]

I'm fine with that if we release #910 with it :)

Sure, will wait for #910 to merge.