fix(android): don't upscale sources without a size past maxSize

[daveallie]

Summary

Fixes #444.

On Android, a Coil-loaded source with no width/height (file://, content://, http(s)://) was scaled up to fill maxSize x maxSize. With the default maxSize of 2048, a 1600x1200 photo came out at 2048x1536. iOS, ImageMarkerCore.fitWithinMax and the maxSize docs all treat it as an upper bound only.

With no source size, the loader requests .size(maxSize, maxSize).scale(Scale.FIT). The request has no target view, so Coil 2 resolves it to Precision.EXACT, and BitmapFactoryDecoder only skips upscaling when an inexact size is allowed. This PR sets Precision.INEXACT for that case only:

• Smaller sources keep their own size, as in 1.x, which used Size.ORIGINAL here.
• Larger sources are still scaled down to fit within maxSize. With an inexact size, Coil still scales down and only skips scaling up.
• Sources with an explicit width/height keep their existing exact sizing, so resource/asset sizing doesn't change.

Validation

• Added MarkerImageLoaderTest.doesNotUpscaleCoilSourceWithoutExplicitSize. It loads the 3x2 test content-provider image with the default maxSize.
  • Before the fix: AssertionError: expected:<3> but was:<2048>
  • After the fix: passes
• MarkerImageLoaderTest + ImageMarkerRendererTest (32 tests) and ImageMarkerJsE2ETest (4 tests, with Metro) all pass on a Pixel 9 API 35 emulator.
  • This includes repeatedlyDownsamplesLargeInputsWithinTheMemoryBound and base64DecodeFitsSourceWithinMaxSizeWithoutCropping, which cover the scale-down path.
• npm run typecheck
• npm run lint
• npx jest (158 tests)