fix(android): escape backup JSON controls

[bhelm]

Summary

• escape every JSON C0 control character in Android backup provenance strings
• preserve named escapes for backspace, form feed, newline, carriage return, and tab, with canonical lower-case \u00xx escapes for the remaining controls
• retain sorted keys, numeric literals, and ordinary manifest/version-event output
• add mirrored Swift and Android byte-contract tests plus Android JSON roundtrip coverage

Normal production values remain build-controlled; the affected inputs require custom/tampered metadata or direct helper use. This keeps the operational scope bounded while restoring the public byte-parity and valid-JSON contract.

Verification

• Swift canonical control: 5/5 passed
• Kotlin RED: 5 tests, exactly 2 expected failures for named controls and the complete C0 corpus
• Kotlin focused GREEN: 5/5 passed
• Kotlin fullDebug: 4,093 tests, 0 failures
• Android full :app:test: 16,372 tests across four variants, 0 failures
• Swift full WhoopStore: 391 tests, 0 failures
• independent frozen-delta review: no P0/P1 findings; functional PASS
• git diff --check: clean

Android execution was serial and bounded: JDK 17, no daemon, one worker, no parallel execution, Kotlin in-process, 1536 MiB heap. Temporary Linux-only Swift build gates were fully reverted before commit. Machine-readable RED/GREEN hash manifests were retained outside the worktree.

Provenance: upstream PR #1422 (d9aae8cb).
Tracks bhelm#86