feat: Add backdrop-filter support for Android

[marcinszalski-callstack]

Summary:

This PR adds JS support for the backdrop-filter style property. It follows the CSS Filters spec as applied to backdrop rendering. The property accepts the same FilterFunction type already used by the filter property, so no new types are introduced — the existing array and string parsing via processFilter is reused directly.

Supported filter functions: blur, brightness, contrast, grayscale, sepia, saturate, invert, hue-rotate, drop-shadow.

Note: opacity() and drop-shadow() are parsed and accepted without error, but are effectively no-ops in a backdrop-filter context — opacity() reveals the unfiltered content beneath, and drop-shadow() operates on the rectangular backdrop image rather than content-shaped output, producing no visible result. This matches expected CSS spec behavior.

Work has been split into three PRs for more convenient reviewing. This part adds Android support.

Changelog:

[ANDROID] [ADDED] - Add backdrop-filter CSS support for Android

Test Plan:

Merge the JS and iOS PRs and run the RNTester app.

• Test the Backdrop Filter screen in RNTester (BackdropFilterExample.js)