body2 TextStyle is deprecated

[Rex-Ferrer]

In MDC-102's Part 6(Make a card collection) and under the Add product data section, the deprecated body2 TextStyle is used in the _buildGridCards(...) method. I recommend changing it to the bodyText2 TextStyle.

Current:

 Text(
    formatter.format(product.price),
    style: theme.textTheme.body2,
  ),

Recommendation:

 Text(
    formatter.format(product.price),
    style: theme.textTheme.bodyText2,
  ),

[rami-a]

In the updated names the body texts swapped, so if it was body2 before it should be bodyText1 now.

[Renzo-Olivares]

Fixed by #189