Fix for voice command that contains no string should be removed

[JulianKast]

Fixes #1675

This PR is [ready] for review.

Risk

This PR makes [minor] API changes.

Testing Plan

• I have verified that I have not introduced new warnings in this PR (or explain why below)
• I have run the unit tests with this PR
• I have tested this PR against Core and verified behavior (if applicable, if not applicable, explain why below).
• I have tested Android, Java SE, and Java EE

Unit Tests

Unit tests were added to VoiceCommandManagerTests.java

Core Tests

Test sending voice commands with extra white space on the front and back for example: " command one ", verify that extra white space is removed and the uploaded voice command is: "command one"
Test sending two voice commands one with an empty string set like " " and one normal one, verify that only the normal voice command is sent to the update operation.
Test sending voice commands only with empty strings, like " ". Verify that an error message is printed out in the logs: "New voice commands are invalid, skipping..."

Core version / branch / commit hash / module tested against: Core 7.1.1
HMI name / version / branch / commit hash / module tested against: Sdl_HMI 5.5.1

Summary

Stripped extra white space from voice commands.
Removes empty strings from being sent in voice commands.

Changelog

Enhancements

• Stripped extra white space from voice commands.
• Removes empty strings from being sent in voice commands.

CLA

• I have signed the CLA

[codecov]

Codecov Report

Merging #1686 (9ee6bab) into develop (4aa6a62) will decrease coverage by 0.12%.
The diff coverage is 93.10%.

@@              Coverage Diff              @@
##             develop    #1686      +/-   ##
=============================================
- Coverage      53.95%   53.83%   -0.13%     
- Complexity      5311     5447     +136     
=============================================
  Files            555      555              
  Lines          24572    25136     +564     
  Branches        3104     3263     +159     
=============================================
+ Hits           13259    13531     +272     
- Misses         10161    10426     +265     
- Partials        1152     1179      +27     

Impacted Files	Coverage Δ	Complexity Δ
.../managers/screen/menu/BaseVoiceCommandManager.java	76.27% <93.10%> (+10.31%)	26.00 <12.00> (+11.00)
...artdevicelink/transport/utl/SdlDeviceListener.java	8.73% <0.00%> (-1.61%)	2.00% <0.00%> (ø%)
...ink/managers/screen/BaseTextAndGraphicManager.java	63.75% <0.00%> (-0.42%)	50.00% <0.00%> (-2.00%)
...va/com/smartdevicelink/exception/SdlException.java	0.00% <0.00%> (ø)	0.00% <0.00%> (ø%)
...icelink/transport/MultiplexBluetoothTransport.java	4.56% <0.00%> (+0.27%)	14.00% <0.00%> (+6.00%)
...martdevicelink/transport/SdlBroadcastReceiver.java	3.62% <0.00%> (+0.38%)	3.00% <0.00%> (+1.00%)
...managers/screen/TextAndGraphicUpdateOperation.java	71.70% <0.00%> (+0.54%)	119.00% <0.00%> (+2.00%)
...rtdevicelink/streaming/video/SdlRemoteDisplay.java	51.21% <0.00%> (+1.21%)	5.00% <0.00%> (ø%)
.../main/java/com/smartdevicelink/util/DebugTool.java	17.20% <0.00%> (+2.15%)	12.00% <0.00%> (+1.00%)
... and 5 more