rcp.branding: Apply plugin.xml amend upon launch

When launching [1] in Eclipse locally, the latter automatically amends
this plugin.xml that way. Persist this likely mandatory amend made by
Eclipse.

[1] tracing.incubator.product

Change-Id: I996f2dafcb8d3b445092dc72ceb11d5d0724c721
Signed-off-by: Marco Miller <marco.miller@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/200779
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>

rcp/org.eclipse.tracecompass.incubator.rcp.branding/plugin.xml

@@ -21,7 +21,7 @@
             </property>
             <property
                   name="aboutText"
-                  value="Trace Compass (Incubator)&#x0A;&#x0A;Version: 0.5.0&#x0A;&#x0A;Copyright (c) 2019, 2022 École Polytechnique de Montréal and others.&#x0A;&#x0A;All rights reserved. This program and the accompanying materials are&#x0A;made available under the terms of the Eclipse Public License 2.0 which&#x0A;accompanies this distribution, and is available at&#x0A;https://www.eclipse.org/legal/epl-2.0/&#x0A;&#x0A;SPDX-License-Identifier: EPL-2.0">
+                  value="Trace Compass (Incubator)&#x0A;&#x0A;Version: 0.5.0&#x0A;&#x0A;Copyright (c) 2019, 2022 École Polytechnique de Montréal and others&#x0A;&#x0A;All rights reserved. This program and the accompanying materials are&#x0A;made available under the terms of the Eclipse Public License 2.0 which&#x0A;accompanies this distribution, and is available at&#x0A;https://www.eclipse.org/legal/epl-2.0/&#x0A;&#x0A;SPDX-License-Identifier: EPL-2.0">
             </property>
             <property
                   name="windowImages"