There is absolutely no requirement to file an iCLA with the Apache Software Foundation in order to use the Apache License v2.0. The iCLA is for contributors to Apache projects. It says so right in the part quoted below. Many projects not carried out as Apache projects use the license. (Compare with using the GPL versus contributing to a Gnu project, the latter generally requiring a license to FSF.)
The license itself suggests all that is needed to apply it to your own work. The ODF Authors are certainly free to do so without any permission or agreement with the ASF. See <http://www.apache.org/licenses/LICENSE-2.0.txt> and its Appendix.
It is also the case that, from the perspective of an Apache project that might have some keen interest in this material ( [;<), non-Apache sources of ALv2-licensed material are treated as 3rd party sources. It just happens that the licenses are highly compatible [;<). The CC-By-Attribution (but not Share-Alike) is also pretty compatible.
Also, independently licensing under ALv2 is *not* the same as contributing it to Apache. (I've registered an iCLA with ASF and I'm an Apache committer, but my independent projects that I'm licensing under ALv2 are not contributions to any Apache project.)
- Dennis