Add Signal Strength to TelephonyMetrics when Data Stall

Bug: 144804770
Test: 1. Build pass.
      2. We can see the SignalStrength when calling doRecovery().
      3. atest DcTrackerTest

      Test Log:
      12-18 16:00:23.398  3661  3661 D DCT-C   : trigger data stall recovery
      12-18 16:00:23.477  3661  3661 D DCT-C   : doRecovery() signalStrength:4
      12-18 16:00:23.478  3661  3661 D DCT-C   : doRecovery() get data call list
      12-18 16:00:33.737  3661  3661 D DCT-C   : trigger data stall recovery
      12-18 16:00:33.748  3661  3661 D DCT-C   : doRecovery() signalStrength:4
      12-18 16:00:33.749  3661  3661 D DCT-C   : doRecovery() get data call list

--------------------------------------------
[1/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testDataCallOnUserDisableRoaming: PASSED (2.188s)
[2/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDataEmergencyApn: PASSED (905ms)
[3/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testCarrierActionSetMeteredApnsEnabled: IGNORED (1ms)
[4/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testRecoveryStepRestartRadio: PASSED (1.333s)
[5/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testUserDisableData: IGNORED (1ms)
[6/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testDDSResetAutoAttach: PASSED (1.760s)
[7/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupNotConnectable: PASSED (1.308s)
[8/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupRestrictedDataDisabled: PASSED (1.308s)
[9/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testFetchDunApn: PASSED (905ms)
[10/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testRecoveryStepPDPReset: PASSED (1.182s)
[11/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testNetworkStatusChangedRecoveryON: PASSED (1.383s)
[12/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testDataRatChangeOOS: PASSED (1.559s)
[13/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testUpdateWaitingApnListOnDataRatChange: PASSED (1.534s)
[14/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testRecoveryStepReRegister: PASSED (1.334s)
[15/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testDataRetry: PASSED (1.761s)
[16/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testDataSetup: PASSED (1.333s)
[17/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testFetchDunApnWithPreferredApnSet: PASSED (906ms)
[18/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDefaultInECBM: PASSED (1.282s)
[19/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testGetDataConnectionState: PASSED (1.257s)
[20/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testUserDisableRoaming: PASSED (1.433s)
[21/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDefaultOnIWLAN: PASSED (1.308s)
[22/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupMeteredDataDisabled: PASSED (1.333s)
[23/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDataMmsAllowedDataDisabled: PASSED (1.836s)
[24/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testNetworkStatusChangedRecoveryOFF: PASSED (1.534s)
[25/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDataUnmeteredDataDisabled: PASSED (1.333s)
[26/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupRestrictedRoamingDisabled: PASSED (1.358s)
[27/27] com.android.internal.telephony.dataconnection.DcTrackerTest#testTrySetupDataUnmeteredDefaultNotSelected: PASSED (1.308s)

Summary
-------
arm64-v8a FrameworksTelephonyTests: Passed: 25, Failed: 0, Ignored: 2, Assumption Failed: 0

All tests passed!

Merged-In: I5b13d62aa8e9375e1db6aff8f639d0827aca8b9a
Change-Id: I5b13d62aa8e9375e1db6aff8f639d0827aca8b9a