WASHINGTON—President Joe Biden announced Wednesday he’s nominating Caroline Kennedy, the daughter of President John F. Kennedy who served as ambassador to Japan during the Obama administration, to serve as ambassador to Australia and Michelle Kwan, the renowned U.S. Olympic figure skater, to serve as his chief envoy to Belize. Kennedy threw her support behind Biden relatively early in the crowded 2020 Democratic primary process. Kennedy in a statement offered gratitude to Solomon Islanders and Australian coast watchers in the Pacific who rescued her father during World War II after his crew’s motor torpedo boat was sunk by the Japanese in August 1943. “If confirmed, I will work hard to repay this debt,” she said. “I look forward to collaborating with the Government of Australia to strengthen our alliance, improve global health and increase vaccine access during this terrible pandemic and to address the urgent climate crisis. I am excited to …