fix(md-datepicker): style fix and applying placeholder

[shivi956]

Styling Fix in md-datepicker and applying custom placeholder to calendar without failing validation for the first time.

Description

The box is always red for the first time , ( we need to add a default value of YYY-MM-DD (placeholder)) but that is also failing on validation .)

Screenshots on the basis :

1. We don't need to send a value attribute to the calender
2. This is for the first time when the input box is not dirty , and the input box is dirty then red is acceptable.

Related Issue

N/A

Motivation and Context

Now we can set the placeholder values and the validation will not fail for the first time.

How Has This Been Tested?

Tested Locally setting up the project

Screenshots:

Before (If applicable):

After

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation update
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Other... Please describe:

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.