Is what I did supervised or unsupervised Machine learning?
The basic idea behind supervised and unsupervised learning is:
In supervised learning, one possesses a training data set that includes the desired target output feature. Examples of popular supervised learning algorithms are linear regression, and support vector classification etc.
In unsupervised learning, we do not possess a training data set with the target output feature i.e. we do not know what our output or results look like. An example is clustering. There are really good explanations out there about this.

LDA is an unsupervised learning algorithm and the process you described can be classified as unsupervised learning. The filtering step that you describe does not make the algorithm supervised because the target smartphones have not been directly correlated to the training data and therefore is only serving as a guide to restrict the cardinality of the target variable.