feat(android): implement BorderDrawable outline

[edusperoni]

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing
• Tests for the changes are included

What is the current behavior?

BorderDrawable does not have an outline

What is the new behavior?

BorderDrawable has an outline

Provides initial support for NativeScript/NativeScript#550

Are there any tests to run?

[manoldonev]

test

[etabakov]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[rdlauer]

Hi - could we get a status update on this PR? Getting pinged about it regularly.

[SvetoslavTsenov]

test

[manoldonev]

@edusperoni our QAs identified a failing ui test triggered by this change:

Actual:

Diff:

Expected:

[manoldonev]

Can be reproduced with this xml markup (correct behavior is that there shouldn't be any grayish left/right border):

<Page class="page"
    navigatingTo="onNavigatingTo"
    xmlns="http://schemas.nativescript.org/tns.xsd">

    <ActionBar class="action-bar">
        <Label class="action-bar-title" text="Home"></Label>
    </ActionBar>

    <GridLayout rows="*,*,*" columns="*,*,*">
        <Button row="1" col="1" textWrap="true" text="border-width: 5 0; border-color: black;"
            style="border-width: 5 0; border-color: black;" />
    </GridLayout>
</Page>

[SvetoslavTsenov]

Hey @edusperoni,
I want to notify you that the NativeScript/tns-core-modules-widgets repository is being moved to the NativeScript/NativeScript repository in an effort to streamline the maintenance and the QA processes. The tns-core-modules-widgets repository will be archived soon. We advise you to open a new PR in the NativeScript/NativeScript with the suggested changes and we will be happy to review it.