Bump third_party/ot-br-posix/repo from `bd15f71` to `722f283` #435

Job	Run time
REPL Tests - Linux	1h 38m 14s
Test Suites - Darwin (no-ble-no-shell-asan-clang)	1h 38m 33s
REPL Tests - Darwin	0s
Test Suites - Darwin (no-ble-no-shell-tsan-clang)	1h 51m 32s
Test Suites - Linux (no-ble-no-shell-tsan-clang)	2h 1m 8s
	7h 9m 27s

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