It *is* overpowered
===

But I agree Dragonborns need some help.

Why is the original weak?
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It is not about the *number* of features a race gets, but how often they come into play and how much they matter<sup>1</sup>

 - Resistance is rare and powerful in 5e, but of course it is hard to know at character creation what will come up most
 - Breath Weapon is used with a secondary stat, has horrible damage, and takes up an action
 - The abilities are not complementary, only Int + Cha would be worse. Beside Paladins, only some niche builds find Str + Cha useful

To make matters worse, Resistance goes against Breath Weapon, in that for the first you should pick something common like fire or poison, for the second something [rare][1] like acid. With the current setup, you should prefer Resistance, as Breath Weapon is close to useless for the following reasons:

 - For any reasonably optimized character, about 3 enemies have to be in the area just to break even with your usual damage output<sup>2</sup>
 - Most of the time so many enemies cluster only around one of your fellow adventurers, whom you do not want to hurt

Why is yours too strong?
===
You gave better Breath Weapon by changing it to a bonus action, _and_ better ability modifiers.    
Either one would have been enough.

As [@Kuerten wrote in his comment][2] to [@fabian's answer][3], the other features do not matter much in the power level, they come up very rarely.  
 Still, I would delete most, leaving maybe one, just to keep it colorful.

Simple fix to the original
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Breath Weapon should either do decent damage, or should cost less.

If you want tactics to be relevant, increase the damage die to d10 from d6. In this case 2 enemies are usually worth an action<sup>3</sup>.   
If you want it to be easy, leave the damage, but make it a bonus action.

Do not change anything else.

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1) Variant Humans were still the best race for most builds even without the extra skill, with only one feature   
2) Dual wielders for example lose their bonus action attack too, if they use their action for breathing   
3) Unless you would have advantage on your attacks


  [1]: https://rpg.stackexchange.com/a/103214/9552
  [2]: https://rpg.stackexchange.com/questions/138048/is-this-version-of-the-dragonborn-race-unbalanced/138050#comment348314_138050
  [3]: https://rpg.stackexchange.com/questions/138048/is-this-version-of-the-dragonborn-race-unbalanced/138050#138050