Removed Jackson dependency

[abhijeetshuklaoist]

Signed-off-by: Abhijeet Shukla abhijeetshuklaoist@gmail.com

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Fixes #506 ☕️

[codecov]

Codecov Report

Merging #508 (7585b9d) into master (1887932) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #508      +/-   ##
============================================
- Coverage     74.09%   74.06%   -0.03%     
+ Complexity     1117     1116       -1     
============================================
  Files            66       66              
  Lines          5883     5884       +1     
  Branches        723      724       +1     
============================================
- Hits           4359     4358       -1     
  Misses         1296     1296              
- Partials        228      230       +2     

Impacted Files	Coverage Δ	Complexity Δ
...a/com/google/cloud/firestore/DocumentSnapshot.java	80.85% <0.00%> (-0.87%)	39.00% <0.00%> (ø%)
.../com/google/cloud/firestore/CustomClassMapper.java	76.68% <0.00%> (-0.17%)	110.00% <0.00%> (-1.00%)

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[schmidt-sebastian]

Another approach for this PR would be to simply drop the JSON parsing from the callsites. The JSON parser is only used in the Unit tests and it seems straightforward to replace its usage. Instead of:

  @Test
  public void primitiveDeserializeString() {
    StringBean bean = deserialize("{'value': 'foo'}", StringBean.class);
    assertEquals("foo", bean.value);
    ...

We could just do:

  @Test
  public void primitiveDeserializeString() {
    StringBean bean = deserialize(map("value",  "foo"), StringBean.class); // 
    assertEquals("foo", bean.value);

  private static <T> T deserialize(Map<String, Object> value, Class<T> clazz) ...

deserialize could also be:

  private static <T> T deserialize(Class<T> clazz, String key, Object value, Object ... moreKeysAndValues) ...

Which would make the callsites even more concise.

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[abhijeetshuklaoist]

@googlebot I fixed it.