Security update for java-1_8_0-openjdk

This update for java-1_8_0-openjdk to version jdk8u252 fixes the following issues: - CVE-2020-2754: Forward references to Nashorn (bsc#1169511) - CVE-2020-2755: Improve Nashorn matching (bsc#1169511) - CVE-2020-2756: Better mapping of serial ENUMs (bsc#1169511) - CVE-2020-2757: Less Blocking Array Queues (bsc#1169511) - CVE-2020-2773: Better signatures in XML (bsc#1169511) - CVE-2020-2781: Improve TLS session handling (bsc#1169511) - CVE-2020-2800: Better Headings for HTTP Servers (bsc#1169511) - CVE-2020-2803: Enhance buffering of byte buffers (bsc#1169511) - CVE-2020-2805: Enhance typing of methods (bsc#1169511) - CVE-2020-2830: Better Scanner conversions (bsc#1169511) - Ignore whitespaces after the header or footer in PEM X.509 cert (bsc#1171352)