Update to Gerrit API 3.5.0.1 and Java 11

to prepare for upgrade to upcoming Gerrit 3.5.1. Gerrit 3.5.x requires Java version 11 or higher.

.settings/org.eclipse.jdt.core.prefs

@@ -10,9 +10,9 @@ org.eclipse.jdt.core.compiler.annotation.nullable.secondary=
 org.eclipse.jdt.core.compiler.annotation.nullanalysis=disabled
 org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
 org.eclipse.jdt.core.compiler.codegen.methodParameters=do not generate
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
 org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
-org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.compliance=11
 org.eclipse.jdt.core.compiler.debug.lineNumber=generate
 org.eclipse.jdt.core.compiler.debug.localVariable=generate
 org.eclipse.jdt.core.compiler.debug.sourceFile=generate
@@ -113,4 +113,4 @@ org.eclipse.jdt.core.compiler.problem.unusedWarningToken=warning
 org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
 org.eclipse.jdt.core.compiler.processAnnotations=enabled
 org.eclipse.jdt.core.compiler.release=disabled
-org.eclipse.jdt.core.compiler.source=1.8
+org.eclipse.jdt.core.compiler.source=11