Manage lifecycle of installed modules

[i-maravic]

When an ApolloModule installs another ApolloModule, it should start managing lifecycles for all the keys from the installed ApolloModule.

Apollo will not manage the installed modules on the service shutdown if we don't do this.

[i-maravic]

@lepistone

[codecov]

Codecov Report

Merging #357 (9b2fcd7) into 1.x (10b98e0) will increase coverage by 0.09%.
The diff coverage is 83.33%.

@@             Coverage Diff              @@
##                1.x     #357      +/-   ##
============================================
+ Coverage     72.04%   72.14%   +0.09%     
- Complexity      673      676       +3     
============================================
  Files           137      137              
  Lines          2862     2868       +6     
  Branches        167      169       +2     
============================================
+ Hits           2062     2069       +7     
+ Misses          763      761       -2     
- Partials         37       38       +1     

Impacted Files	Coverage Δ
...om/spotify/apollo/module/AbstractApolloModule.java	88.88% <83.33%> (+13.88%)	⬆️

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[caesar-ralf]

nitty-pick: What do you think about repeating this at line 462? Something like this could be possible:

try (Service.Instance instance = service.start()) {
    assertThat(childCreated.get(), is(true));
    assertThat(childClosed.get(), is(false));
    instance.getSignaller().signalShutdown();  
    instance.waitForShutdown();    
}

From what I am looking in the code I think it should be fine as they are set in the moment you're creating the instance of the class. What do you think?

[klaraward]

Reviewed and approved by weaver squad.
<jinx>Since the keys are stored in a ImmutableSet and then a LinkedHashSet we are positive the ordering of the lifecycle managed keys is preserved and this PR should not lead to any big surprises in the shutdown sequence of an Apollo service.</jinx>