Ignore temporary build artifacts during maven builds

Add .polyglot.build.properties and .tycho-consumer-pom.xml to .gitignore
because they are temporary build artifacts and are not meant to be under
source control.

Change-Id: Ieb61777d5018b8e9ea6dd99ed274e9996c40c43f
Signed-off-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/197831
Tested-by: Marco Miller <marco.miller@ericsson.com>
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Reviewed-by: Marco Miller <marco.miller@ericsson.com>

.gitignore

@@ -1,7 +1,9 @@
 # LC_COLLATE=C sort
 */.settings/org.sonar.ide.eclipse.core.prefs
 .DS_Store
+.polyglot.build.properties
 .pydevproject
+.tycho-consumer-pom.xml
 bin/
 target/
 workspace/