Supporters of imprisoned academic Yang Hengjun are vowing to renew their push for his freedom after the long-awaited release of Australian journalist Cheng Lei from jail in China. Key points: Writer Yang Hengjun was sentenced for espionage in 2021 but has yet to receive a verdict Writer Yang Hengjun was sentenced for espionage in 2021 but has yet to receive a verdict Details surrounding released journalist Cheng Lei's case remain unclear Details surrounding released journalist Cheng Lei's case remain unclear Other Australians are still being detained in China Prime Minister Anthony Albanese announced on Wednesday that Ms Lei had returned…