fix: schema

Author: Mesh-ach

src/webapp/validation_schemas/base_schema.json

@@ -32,7 +32,7 @@
             "checks": []
           },
           "first_generation_student": {
-            "dtype": "string",
+            "dtype": "category",
             "coerce": true,
             "nullable": true,
             "required": false,

src/webapp/validation_schemas/pdp_schema_extension.json

@@ -515,23 +515,23 @@
               "checks": []
             },
             "years_to_associates_or_certificate_at_cohort_inst": {
-              "dtype": "category",
+              "dtype": "string",
               "coerce": true,
               "nullable": true,
               "required": true,
               "aliases": [],
               "checks": []
             },
             "years_to_associates_or_certificate_at_other_inst": {
-              "dtype": "category",
+              "dtype": "string",
               "coerce": true,
               "nullable": true,
               "required": true,
               "aliases": [],
               "checks": []
             },
             "years_to_bachelor_at_other_inst": {
-              "dtype": "category",
+              "dtype": "string",
               "coerce": true,
               "nullable": true,
               "required": true,