Fix a crash when RPC encryption starts and callback when RPCs fail due to RPC encryption

[joeljfischer]

Fixes #1966, #1971

Risk

This PR makes no API changes.

Testing Plan

• I have verified that I have not introduced new warnings in this PR (or explain why below)
• I have run the unit tests with this PR
• I have tested this PR against Core and verified behavior (if applicable, if not applicable, explain why below).

Unit Tests

Unit tests were updated to ensure that the callback is handled correctly.

Core Tests

Tested an RPC encrypted app with PutFile encrypted. Ensured that no crashes occurred and the app set up correctly.

Core version / branch / commit hash / module tested against: v7.1.0-RC.1 (0df66080512cbe76ee5d4872910a54adf3ca1f36)
HMI name / version / branch / commit hash / module tested against: sdl_hmi v5.5.0

Summary

1. SDLLifecycleManager now ignores RPC StartServiceACK if we're already connected instead of crashing.
2. Updates SDLProtocol sendRPC: to pass back an error and return a success BOOL so that the handler can be called in the SDLLifecycleManager if the RPC fails to send in the protocol layer.

Changelog

Bug Fixes

• Fixed RPC encryption causing a crash when the second RPC StartServiceACK is received.
• Fixed not calling an RPC request handler if the message failed to send in the protocol layer of the library.

Tasks Remaining:

• Add a unit test for the RPC failing to send in the protocol layer should call the handler.
• Smoke test on Core v7.1.0
• Smoke test on Sync 3.4

CLA

• I have signed the CLA

[codecov]

Codecov Report

Merging #1972 (1fa7c01) into hotfix/7.1.1 (62d1859) will increase coverage by 0.02%.
The diff coverage is 50.98%.

@@               Coverage Diff                @@
##           hotfix/7.1.1    #1972      +/-   ##
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+ Coverage         83.66%   83.69%   +0.02%     
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  Files               441      441              
  Lines             22543    22564      +21     
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+ Hits              18861    18885      +24     
+ Misses             3682     3679       -3     

[NicoleYarroch]

I small documentation fix requested.