Revert "[icu] not building BUILD_DATA should still have an install ta…

[hyp]

…rget"

This reverts commit 4c12ddf.

Revert "[icu] add a BUILD_DATA flag to let android build skip building data"

This reverts commit 955e5a9.

This wasn't the right approach for ICU for android on Windows.

[compnerd]

I'm confused, shouldn't the install bits remain and the condition around it be removed? (along with the early return if BUILD_DATA is defined).

[compnerd]

Discussed offline - there is a second copy of the install call at the end of the file that accomplishes this.