fix: Initialize localStorage idling value to false in constructor

[roupify]

If AutoResume.NotIdle is set, the idling value must be to false in localStorage, otherwise, on startup, if the value is at true, no interrupt will emit.

Please check if the PR fulfills these requirements

• [X] The commit message follows our guidelines: https://github.com/HackedByChinese/ng2-idle/blob/master/CONTRIBUTING.md#pr
• [X] Tests for the changes have been added (for bug fixes / features)
• [X] Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x")

[X] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior? (You can also link to an open issue here)

Idling initial value wasn't set in localStorage, only in idle property.

What is the new behavior?

We initialize the idling value in localStorage at startup.

Does this PR introduce a breaking change? (check one with "x")

[ ] Yes
[X] No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[coveralls]

Coverage remained the same at 99.326% when pulling ab7143316d5c759831a9d37a2030ebd0c6834721 on rousseaufiliong:master into e3a0b2b3a6b81ac435a949d83af02c740337f2d3 on HackedByChinese:master.