deps: update dependency org.apache.httpcomponents:httpcore to v4.4.15 (#1523)

Author: renovate-bot

pom.xml

@@ -570,7 +570,7 @@
     <project.guava.version>30.1.1-android</project.guava.version>
     <project.xpp3.version>1.1.4c</project.xpp3.version>
     <project.httpclient.version>4.5.13</project.httpclient.version>
-    <project.httpcore.version>4.4.14</project.httpcore.version>
+    <project.httpcore.version>4.4.15</project.httpcore.version>
     <project.opencensus.version>0.28.0</project.opencensus.version>
     <project.root-directory>..</project.root-directory>
     <deploy.autorelease>false</deploy.autorelease>