For #13911: Fix resolving color attribute for title and description.

For SDK < 23 color attr cannot be resolved in selectors.

app/src/main/java/org/mozilla/fenix/ext/SpannableString.kt

@@ -9,7 +9,7 @@ import android.text.Spannable
 import android.text.SpannableString
 import android.text.style.AbsoluteSizeSpan
 import android.text.style.ForegroundColorSpan
-import androidx.core.content.ContextCompat
+import mozilla.components.support.ktx.android.content.getColorFromAttr
 import mozilla.components.support.ktx.android.util.dpToPx
 
 fun SpannableString.setTextSize(context: Context, textSize: Int) =
@@ -23,10 +23,7 @@ fun SpannableString.setTextSize(context: Context, textSize: Int) =
 fun SpannableString.setTextColor(context: Context, colorResId: Int) =
     this.setSpan(
         ForegroundColorSpan(
-            ContextCompat.getColor(
-                context,
-                colorResId
-            )
+            context.getColorFromAttr(colorResId)
         ),
         0,
         this.length,

app/src/main/java/org/mozilla/fenix/onboarding/OnboardingRadioButton.kt

@@ -71,14 +71,14 @@ class OnboardingRadioButton(
 
         val spannableTitle = SpannableString(resources.getString(title))
         spannableTitle.setTextSize(context, TITLE_TEXT_SIZE)
-        spannableTitle.setTextColor(context, R.color.primary_state_list_text_color)
+        spannableTitle.setTextColor(context, R.attr.primaryText)
 
         builder.append(spannableTitle)
 
         if (description != 0) {
             val spannableDescription = SpannableString(resources.getString(description))
             spannableDescription.setTextSize(context, DESCRIPTION_TEXT_SIZE)
-            spannableDescription.setTextColor(context, R.color.secondary_state_list_text_color)
+            spannableDescription.setTextColor(context, R.attr.secondaryText)
             builder.append("\n")
             builder.append(spannableDescription)
         }