[RNMobile] apply flex to prevent caption overlap in Gallery block

[jbinda]

Description

Apply flex style to View that hold content of Gallery on mobile. It prevents gallery caption being covered by other block border and keep proper spacing between blocks

Please also refer to:
Related gutenberg-mobile PR
Related gutenberg-mobile issue

How has this been tested?

1. Add Gallery block
2. Add gallery caption
3. Start adding new block, changing order and selection
4. See that Gallery caption is not being overlapped by next block border

Screenshots

• Before

• After

Types of changes

Bug fix

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[github-actions]

Size Change: 0 B

Total Size: 857 kB

ℹ️ View Unchanged

Filename	Size	Change
build/a11y/index.js	998 B	0 B
build/annotations/index.js	3.43 kB	0 B
build/api-fetch/index.js	3.39 kB	0 B
build/autop/index.js	2.58 kB	0 B
build/blob/index.js	620 B	0 B
build/block-directory/index.js	6.02 kB	0 B
build/block-directory/style-rtl.css	760 B	0 B
build/block-directory/style.css	760 B	0 B
build/block-editor/index.js	100 kB	0 B
build/block-editor/style-rtl.css	10.9 kB	0 B
build/block-editor/style.css	10.9 kB	0 B
build/block-library/editor-rtl.css	7.23 kB	0 B
build/block-library/editor.css	7.24 kB	0 B
build/block-library/index.js	111 kB	0 B
build/block-library/style-rtl.css	7.42 kB	0 B
build/block-library/style.css	7.43 kB	0 B
build/block-library/theme-rtl.css	669 B	0 B
build/block-library/theme.css	671 B	0 B
build/block-serialization-default-parser/index.js	1.65 kB	0 B
build/block-serialization-spec-parser/index.js	3.1 kB	0 B
build/blocks/index.js	57.5 kB	0 B
build/components/index.js	191 kB	0 B
build/components/style-rtl.css	15.7 kB	0 B
build/components/style.css	15.7 kB	0 B
build/compose/index.js	6.21 kB	0 B
build/core-data/index.js	10.6 kB	0 B
build/data-controls/index.js	1.04 kB	0 B
build/data/index.js	8.2 kB	0 B
build/date/index.js	5.37 kB	0 B
build/deprecated/index.js	772 B	0 B
build/dom-ready/index.js	568 B	0 B
build/dom/index.js	3.06 kB	0 B
build/edit-post/index.js	91.2 kB	0 B
build/edit-post/style-rtl.css	8.47 kB	0 B
build/edit-post/style.css	8.46 kB	0 B
build/edit-site/index.js	5.07 kB	0 B
build/edit-site/style-rtl.css	2.53 kB	0 B
build/edit-site/style.css	2.53 kB	0 B
build/edit-widgets/index.js	4.43 kB	0 B
build/edit-widgets/style-rtl.css	2.58 kB	0 B
build/edit-widgets/style.css	2.58 kB	0 B
build/editor/editor-styles-rtl.css	381 B	0 B
build/editor/editor-styles.css	382 B	0 B
build/editor/index.js	44 kB	0 B
build/editor/style-rtl.css	3.97 kB	0 B
build/editor/style.css	3.96 kB	0 B
build/element/index.js	4.45 kB	0 B
build/escape-html/index.js	733 B	0 B
build/format-library/index.js	6.96 kB	0 B
build/format-library/style-rtl.css	502 B	0 B
build/format-library/style.css	502 B	0 B
build/hooks/index.js	1.93 kB	0 B
build/html-entities/index.js	621 B	0 B
build/i18n/index.js	3.49 kB	0 B
build/is-shallow-equal/index.js	710 B	0 B
build/keyboard-shortcuts/index.js	2.3 kB	0 B
build/keycodes/index.js	1.69 kB	0 B
build/list-reusable-blocks/index.js	2.99 kB	0 B
build/list-reusable-blocks/style-rtl.css	226 B	0 B
build/list-reusable-blocks/style.css	226 B	0 B
build/media-utils/index.js	4.84 kB	0 B
build/notices/index.js	1.58 kB	0 B
build/nux/index.js	3.01 kB	0 B
build/nux/style-rtl.css	616 B	0 B
build/nux/style.css	613 B	0 B
build/plugins/index.js	2.54 kB	0 B
build/primitives/index.js	1.5 kB	0 B
build/priority-queue/index.js	780 B	0 B
build/redux-routine/index.js	2.84 kB	0 B
build/rich-text/index.js	14.3 kB	0 B
build/server-side-render/index.js	2.55 kB	0 B
build/shortcode/index.js	1.7 kB	0 B
build/token-list/index.js	1.27 kB	0 B
build/url/index.js	4.01 kB	0 B
build/viewport/index.js	1.61 kB	0 B
build/warning/index.js	1.14 kB	0 B
build/wordcount/index.js	1.18 kB	0 B

_{compressed-size-action}

[geriux]

LGTM! Thanks for this quick fix! Tested both on iOS and Android and on the demo iOS App.